Electrical and Electronics Engineering publications abstract of: 09-2017 sorted by title, page: 14

» Scheduling Independent Moldable Tasks on Multi-Cores with GPUs
Abstract:
We present a new approach for scheduling independent tasks on multiple CPUs and multiple GPUs. The tasks are assumed to be parallelizable on CPUs using the moldable model: the final number of cores allotted to a task can be decided and set by the scheduler. More precisely, we design an algorithm aiming at minimizing the makespan—the maximum completion time of all tasks—for this scheduling problem. The proposed algorithm combines a dual approximation scheme with a fast integer linear program (ILP). It determines both the partitioning of the tasks, i.e., whether a task should be mapped to CPUs or a GPU, and the number of CPUs allotted to a moldable task if mapped to the CPUs. A worst-case analysis shows that the algorithm has an approximation ratio of . Since the time complexity of the ILP-based algorithm could be non-polynomial, we also present a polynomial-time algorithm with an approximation ratio of . We complement the theoretical analysis of our two novel algorithms with a simulation study. In these simulations, we compare our algorithms to a modified version of the classical HEFT algorithm, which we adapted to handle moldable tasks. The simulation results show that our algorithm with the -approximation ratio produces significantly shorter schedules than the modified HEFT for most of the instances. In addition, our results provide evidence that our ILP-based algorithm can solve lar- er problem instances in a reasonable amount of time.
Autors: Raphaël Bleuse;Sascha Hunold;Safia Kedad-Sidhoum;Florence Monna;Grégory Mounié;Denis Trystram;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Sep 2017, volume: 28, issue:9, pages: 2689 - 2702
Publisher: IEEE
 
» Scheduling With Predictable Link Reliability for Wireless Networked Control
Abstract:
Predictable link reliability is required for wireless networked control, yet co-channel interference remains a major source of uncertainty in wireless link reliability. Formulated specifically for distributed predictable control of co-channel interference, the physical-ratio-K (PRK) interference model integrates the protocol model’s locality and the physical model’s high fidelity while addressing their weaknesses, and it transforms interference control in arbitrary networks to a problem involving coordination between close-by nodes only. To apply the PRK model in real-world settings, we design protocol PRKS that addresses the challenges of model instantiation and protocol signaling in PRK-based scheduling. In particular, PRKS uses a control-theoretic approach to instantiate the PRK model in dynamic uncertain networks, uses local signal maps to address the challenges of large interference range and anisotropic asymmetric wireless communication, and leverages the different timescales of PRK model adaptation and data transmission to decouple protocol signaling from data transmission. Through testbed-based measurement study, we show that, unlike existing scheduling protocols where link reliability is unpredictable and the ratio of links whose reliability meets application requirements can be as low as 0%, PRKS enables predictably high link reliability (e.g., 95%) for all the links in different network and environmental conditions without a priori knowledge of these conditions. Through local distributed coordination, PRKS also achieves a channel spatial reuse very close to what is enabled by the state-of-the-art centralized scheduler while ensuring the required link reliability. By ensuring the required link reliability in scheduling, PRKS also enables a lower communication delay and a higher network throughput than existing scheduling protocols.
Autors: Hongwei Zhang;Xiaohui Liu;Chuan Li;Yu Chen;Xin Che;Le Yi Wang;Feng Lin;George Yin;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 6135 - 6150
Publisher: IEEE
 
» SDN-Based Traffic Aware Placement of NFV Middleboxes
Abstract:
Network function virtualization (NFV) enables flexible deployment of middleboxes as virtual machines running on general hardware. Since different middleboxes may change the volume of processed traffic in different ways, improper deployment of NFV middleboxes will result in hot spots and congestion. In this paper, we study the traffic changing effects of middleboxes, and propose software-defined networking based middlebox placement solutions to achieve optimal load balancing. We formulate the traffic aware middlebox placement (TAMP) problem as a graph optimization problem with the objective to minimize the maximum link load ratio. First, we solve the TAMP problem when the flow paths are predetermined, such as the case in a tree. For a single flow, we propose the least-first-greatest-last (LFGL) rule and prove its optimality; for multiple flows, we first show the NP-hardness of the problem, and then propose an efficient heuristic. Next, for the general TAMP problem without predetermined flow paths, we prove that it is NP-hard even for a single flow, and propose the LFGL based MinMax routing algorithm by integrating LFGL with MinMax routing. We use a joint emulation and simulation approach to evaluate the proposed solutions, and present extensive experimental and simulation results to demonstrate the effectiveness of our design.
Autors: Wenrui Ma;Jonathan Beltran;Zhenglin Pan;Deng Pan;Niki Pissinou;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 528 - 542
Publisher: IEEE
 
» Sea Ice Detection Using U.K. TDS-1 GNSS-R Data
Abstract:
A sea ice detection algorithm developed using the U.K. TechDemoSat-1 (U.K. TDS-1) global navigation satellite systems (GNSSs)-reflectometry data over the Arctic and Antarctic regions is presented. It is based on measuring the similarity of the received GNSS reflected waveform or delay Doppler map (DDM) to the coherent reflection model waveform. Over the open ocean, the scattered signal has a diffusive, incoherent nature; it is described by the rough surface scattering model based on the geometric optics and the Gaussian statistics for the ocean surface slopes. Over sea ice and, in particular, newly formed sea ice, the scattered signal acquires a coherence, which is characteristic for a surface with large flat areas. In order to measure the similarity of the received waveform or DDM, to the coherent reflection model, three different estimators are presented: the normalized DDM average, the trailing edge slope (TES), and the matched filter approach. Here, a probabilistic study is presented based on a Bayesian approach using two different and independent ground-truth data sets. This approach allows one to thoroughly assess the performance of the estimators. The best results are achieved for both the TES and the matched filter approach with a probability of detection of 98.5%, a probability of false alarm of ~ 3.6%, and a probability of error of 2.5%. However, the matched filter approach is preferred due to its simplicity. Data from AMSR2 processed using the Arctic Radiation and Turbulence Interaction STudy Sea Ice algorithm and from an Special Sensor Microwave Imager/Sounder radiometer processed by Ocean and Sea Ice SAF have been used as ground truth. A pixel has been classified as a sea ice pixel if the sea ice concentration (SIC) in it was larger than 15%. The measurement of the SIC is also assessed in this paper, but the nature of the U.K. TDS-1 data (lack of - alibrated data) does not allow to make any specific conclusions about the SIC.
Autors: Alberto Alonso-Arroyo;Valery U. Zavorotny;Adriano Camps;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 4989 - 5001
Publisher: IEEE
 
» Sea Ice Drift Tracking From Sequential SAR Images Using Accelerated-KAZE Features
Abstract:
In this paper, we propose a feature-tracking algorithm for sea ice drift retrieval from a pair of sequential satellite synthetic aperture radar (SAR) images. The method is based on feature tracking comprising feature detection, description, and matching steps. The approach exploits the benefits of nonlinear multiscale image representations using accelerated-KAZE (A-KAZE) features, a method that detects and describes image features in an anisotropic scale space. We evaluated several state-of-the-art feature-based algorithms, including A-KAZE, Scale Invariant Feature Transform (SIFT), and a very fast feature extractor that computes binary descriptors known as Oriented FAST and Rotated BRIEF (ORB) on dual polarized Sentinel-1A C-SAR extra wide swath mode data over the Arctic. The A-KAZE approach outperforms both ORB and SIFT up to an order of magnitude in ice drift. The experimental results showed high relevance of the proposed algorithm for retrieval of ice drift at subkilometre resolution from a pair of SAR images with 100-m pixel size. From this paper, we found that feature tracking using nonlinear scale-spaces is preferable due to its high efficiency against noise with respect to image features compared with other existing feature tracking alternatives that make use of Gaussian or linear scale spaces.
Autors: Denis Demchev;Vladimir Volkov;Eduard Kazakov;Pablo F. Alcantarilla;Stein Sandven;Viktoriya Khmeleva;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 5174 - 5184
Publisher: IEEE
 
» Security Analysis of Password-Authenticated Key Retrieval
Abstract:
A PAKR (Password-Authenticated Key Retrieval) protocol and its multi-server system allow one party (say, client), who has a memorable password, to retrieve a long-term static key in an exchange of messages with at least one other party (say, server) that has a private key associated with the password. In this paper, we analyze the only PAKR (named as PKRS-1) standardized in IEEE 1363.2 [9] and its multi-server system (also, [12] ) by showing that any passive/active attacker can find out the client’s password and the static key with off-line dictionary attacks. This result contradicts the security claims made for PKRS-1 (see Clause 10.2 of IEEE 1363.2 [9] ).
Autors: SeongHan Shin;Kazukuni Kobara;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Sep 2017, volume: 14, issue:5, pages: 573 - 576
Publisher: IEEE
 
» Segment and Conflict Aware Page Allocation and Migration in DRAM-PCM Hybrid Main Memory
Abstract:
Phase change memory (PCM), given its nonvolatility, potential high density, and low standby power, is a promising candidate to be used as main memory in next generation computer systems. However, to hide its shortcomings of limited endurance and slow write performance, state-of-the-art solutions tend to construct a dynamic RAM (DRAM)-PCM hybrid memory and place write-intensive pages in DRAM. While existing optimizations to this hybrid architecture focus on tuning DRAM configurations to reduce the number of write operations to PCM, this paper explores the interactions between DRAM and PCM to improve both the performance and the endurance of a DRAM-PCM hybrid main memory. Specifically, it exploits the flexibility of mapping virtual pages to physical pages, and develops a proactive strategy to allocate pages taking both program segments and DRAM conflict misses into consideration, thus distributing those heavily written pages across different DRAM sets. Meanwhile, a lifetime-aware DRAM replacement algorithm and a conflict-aware page remapping strategy are proposed to further reduce DRAM misses and PCM writes. Experiments confirm that the proposed techniques are able to improve average memory hit time and reduce maximum PCM write counts thus enhancing both performance and lifetime of a DRAM-PCM hybrid main memory.
Autors: Hoda Aghaei Khouzani;Fateme S. Hosseini;Chengmo Yang;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Sep 2017, volume: 36, issue:9, pages: 1458 - 1470
Publisher: IEEE
 
» Segmentation and Quantification for Angle-Closure Glaucoma Assessment in Anterior Segment OCT
Abstract:
Angle-closure glaucoma is a major cause of irreversible visual impairment and can be identified by measuring the anterior chamber angle (ACA) of the eye. The ACA can be viewed clearly through anterior segment optical coherence tomography (AS-OCT), but the imaging characteristics and the shapes and locations of major ocular structures can vary significantly among different AS-OCT modalities, thus complicating image analysis. To address this problem, we propose a data-driven approach for automatic AS-OCT structure segmentation, measurement, and screening. Our technique first estimates initial markers in the eye through label transfer from a hand-labeled exemplar data set, whose images are collected over different patients and AS-OCT modalities. These initial markers are then refined by using a graph-based smoothing method that is guided by AS-OCT structural information. These markers facilitate segmentation of major clinical structures, which are used to recover standard clinical parameters. These parameters can be used not only to support clinicians in making anatomical assessments, but also to serve as features for detecting anterior angle closure in automatic glaucoma screening algorithms. Experiments on Visante AS-OCT and Cirrus high-definition-OCT data sets demonstrate the effectiveness of our approach.
Autors: Huazhu Fu;Yanwu Xu;Stephen Lin;Xiaoqin Zhang;Damon Wing Kee Wong;Jiang Liu;Alejandro F. Frangi;Mani Baskaran;Tin Aung;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Sep 2017, volume: 36, issue:9, pages: 1930 - 1938
Publisher: IEEE
 
» Segmentation- and Annotation-Free License Plate Recognition With Deep Localization and Failure Identification
Abstract:
Automated license plate recognition (ALPR) is essential in several roadway imaging applications. For ALPR systems deployed in the United States, variation between jurisdictions on character width, spacing, and the existence of noise sources (e.g., heavy shadows, non-uniform illumination, various optical geometries, poor contrast, and so on) present in LP images makes it challenging for the recognition accuracy and scalability of ALPR systems. Font and plate-layout variation across jurisdictions further adds to the difficulty of proper character segmentation and increases the level of manual annotation required for training classifiers for each state, which can result in excessive operational overhead and cost. In this paper, we propose a new ALPR workflow that includes novel methods for segmentation- and annotation-free ALPR, as well as improved plate localization and automation for failure identification. Our proposed workflow begins with localizing the LP region in the captured image using a two-stage approach that first extracts a set of candidate regions using a weak sparse network of winnows classifier and then filters them using a strong convolutional neural network (CNN) classifier in the second stage. Images that fail a primary confidence test for plate localization are further classified to identify localization failures, such as LP not present, LP too bright, LP too dark, or no vehicle found. In the localized plate region, we perform segmentation and optical character recognition (OCR) jointly by using a probabilistic inference method based on hidden Markov models (HMMs) where the most likely code sequence is determined by applying the Viterbi algorithm. In order to reduce manual annotation required for training classifiers for OCR, we propose the use of either artificially generated synthetic LP images or character samples acquired by trained ALPR systems already operating in other sites. The performance gap due to differences between training and target- domain distributions is minimized using an unsupervised domain adaptation. We evaluated the performance of our proposed methods on LP images captured in several US jurisdictions under realistic conditions.
Autors: Orhan Bulan;Vladimir Kozitsky;Palghat Ramesh;Matthew Shreve;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Sep 2017, volume: 18, issue:9, pages: 2351 - 2363
Publisher: IEEE
 
» Self-Optimizing IoT Wireless Video Sensor Node With In-Situ Data Analytics and Context-Driven Energy-Aware Real-Time Adaptation
Abstract:
It is well understood that data-acquisition by distributed sensors and subsequent transmission of all the acquired data to the cloud will produce a “data deluge” in next-generation wireless networks leading to immense network congestion, and data back-logs on the server which will prevent real-time processing and control. This motivates in situ data analytics in energy-constrained wireless sensor nodes that can perform context-aware acquisition and processing of data; and transmit data only when required. This paper presents a camera-based wireless sensor node with a self-optimizing end-to-end computation and communication design, targeted for surveillance applications. We demonstrate support for multiple feature-extraction and classification algorithms, tunable processing depth and power amplifier gain. Depending on the amount of information content, accuracy targets and condition of the wireless channel, the system choses the minimum-energy operating-point by dynamically optimizing the amount of processing done on the sensor itself. We demonstrate a complete system with ADI ADSP-BF707 image processor, OV7670 camera sensor, and USRP B200 software defined radio; and achieve reduction in energy consumption compared with a baseline design.
Autors: Ningyuan Cao;Saad Bin Nasir;Shreyas Sen;Arijit Raychowdhury;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2470 - 2480
Publisher: IEEE
 
» Semi-Analytical Modelling of Linear Mode Coupling in Few-Mode Fibers
Abstract:
This paper reviews and extends a method for the semi-analytical solution of the coupled linear differential equations that describe the linear mode coupling arising in few-mode fibers due to waveguide imperfections. The semi-analytical solutions obtained proved to be accurate when compared to numerical solution methods. These solutions were integrated into a multisection model with split-steps for mode dispersion and mode coupling. Simulations using this model matched the analytical predictions for the statistics of group-delays in few-mode fiber links, considering different coupling regimes with and without mode delay management.
Autors: Filipe Marques Ferreira;Christian S. Costa;Stylianos Sygletos;Andrew D. Ellis;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:18, pages: 4011 - 4022
Publisher: IEEE
 
» Semi-supervised Stacked Label Consistent Autoencoder for Reconstruction and Analysis of Biomedical Signals
Abstract:
Objective: An autoencoder-based framework that simultaneously reconstruct and classify biomedical signals is proposed. Previous work has treated reconstruction and classification as separate problems. This is the first study that proposes a combined framework to address the issue in a holistic fashion. Methods: For telemonitoring purposes, reconstruction techniques of biomedical signals are largely based on compressed sensing (CS); these are “designed” techniques where the reconstruction formulation is based on some “assumption” regarding the signal. In this study, we propose a new paradigm for reconstruction—the reconstruction is “learned,” using an autoencoder; it does not require any assumption regarding the signal as long as there is sufficiently large training data. But since the final goal is to analyze/classify the signal, the system can also learn a linear classification map that is added inside the autoencoder. The ensuing optimization problem is solved using the Split Bregman technique. Results: Experiments were carried out on reconstructing and classifying electrocardiogram (ECG) (arrhythmia classification) and EEG (seizure classification) signals. Conclusion: Our proposed tool is capable of operating in a semi-supervised fashion. We show that our proposed method is better in reconstruction and more than an order magnitude faster than CS based methods; it is capable of real-time operation. Our method also yields better results than recently proposed classification methods. Significance: This is the first study offering an alternative to CS-based reconstruction. It also shows that the representation learning approach can yield better results than traditional methods that use hand-crafted features for signa- analysis.
Autors: Anupriya Gogna;Angshul Majumdar;Rabab Ward;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Sep 2017, volume: 64, issue:9, pages: 2196 - 2205
Publisher: IEEE
 
» Semiparametric Decolorization With Laplacian-Based Perceptual Quality Metric
Abstract:
While the RGB2GRAY conversion with fixed parameters is a classical and widely used tool for image decolorization, recent studies showed that adapting weighting parameters in a two-order multivariance polynomial model has great potential to improve the conversion ability. In this paper, by viewing the two-order model as the sum of three subspaces, it is observed that the first subspace in the two-order model has the dominating importance and the second and the third subspace can be seen as refinement. Therefore, we present a semiparametric strategy to take advantage of both the RGB2GRAY and the two-order models. In the proposed method, the RGB2GRAY result on the first subspace is treated as an immediate grayed image, and then the parameters in the second and the third subspace are optimized. Experimental results show that the proposed approach is comparable to other state-of-the-art algorithms in both quantitative evaluation and visual quality, especially for images with abundant colors and patterns. This algorithm also exhibits good resistance to noise. In addition, instead of the color contrast preserving ratio using the first-order gradient for decolorization quality metric, the color contrast correlation preserving ratio utilizing the second-order gradient is calculated as a new perceptual quality metric.
Autors: Qiegen Liu;Peter Xiaoping Liu;Yuhao Wang;Henry Leung;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Sep 2017, volume: 27, issue:9, pages: 1856 - 1868
Publisher: IEEE
 
» Sensing Characteristic of Arrayed Flexible Indium Gallium Zinc Oxide Lactate Biosensor Modified by Magnetic Beads
Abstract:
In this paper, we proposed an arrayed flexible lactate biosensor, and indium gallium zinc oxide (IGZO) was used as the sensing film. The screen-printed technology was used to miniaturize the reference electrode and conductive wires. Lactate dehydrogenase and nicotinamide adenine dinucleotide were used to deposit enzyme membrane on IGZO sensing film to catalyze lactate. In the measurement, the arrayed flexible IGZO lactate biosensor was immersed in the lactate solutions, which concentrations were 0.2, 0.7, 1.3, 2, and 3 mM, respectively. The average sensitivity and linearity of lactate biosensor were 114.900 mV/decade and 0.948, respectively.
Autors: Jung-Chuan Chou;Hsiang-Yi Chen;Yi-Hung Liao;Chih-Hsien Lai;Min-Siang Huang;Jian-Syun Chen;Siao-Jie Yan;Cian-Yi Wu;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5920 - 5926
Publisher: IEEE
 
» Sensitivity Analysis and Uncertainty Mitigation of Photonic Integrated Circuits
Abstract:
Unavoidable statistical variations in fabrication processes can have a strong effect on the functionality of fabricated photonic circuits and on fabrication yield. It is hence essential to consider these uncertainties during design in order to predict and control the statistical behavior of the circuits. In this paper, we exploit elementary effect test and variance-based sensitivity analysis to investigate the behavior of a photonic circuit under fabrication uncertainties, with the aim to identify the most critical parameters affecting circuit performances. As an example, we perform the sensitivity analysis on the 3-dB bandwidth of two different filter designs considering random deviations of the waveguides width and couplers' gap. The information obtained from the analysis is then used to isolate the most critical parameters of the circuits and to estimate and reduce the cost of postfabrication correction of the process variability.
Autors: Abi Waqas;Daniele Melati;Andrea Melloni;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:17, pages: 3713 - 3721
Publisher: IEEE
 
» Sensitivity of an Active Antenna Array Element for the Low-Frequency Radio Telescope GURT
Abstract:
The recently developed new generation, low-frequency Giant Ukrainian Radio Telescope (GURT) is built nearby the well-known Ukrainian T-shaped Radio Telescope. The new facility employs a phased antenna array composed of many subarrays of active antenna elements. In this paper, the parameters of the active antenna used as array element are studied, with special attention paid to sensitivity. The electrical and noise parameters are calculated using computer simulation and wave techniques for noise modeling of two-port networks. The results of numerical calculations of the sensitivity are given in terms of the sky noise dominance (SND) and system equivalent flux density of the GURT element within 10–80 MHz. The calculated results are compared with in situ measurements.
Autors: Peter L. Tokarsky;Alexander A. Konovalenko;Serge N. Yerin;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4636 - 4644
Publisher: IEEE
 
» Sensitivity of NDVI-Based Spatial Downscaling Technique of Coarse Precipitation to Some Mediterranean Bioclimatic Stages
Abstract:
This letter attempts to explore the potential sensitivity of the well-known spatial downscaling technique of coarse precipitation data to some bioclimatic stages of the Mediterranean area. For this purpose, first, an open data set covering a period of 15 years, including TRMM3B43, normalized difference vegetation index (NDVI), DEM, and rain gauge station measurements, was prepared. Then the NDVI-based spatial downscaling technique was applied over Morocco without taking account of bioclimatic stages. Second, based on the same data set, the key step of the downscaling approach (regression between TRMM3B43 and NDVI) was analyzed in five bioclimatic stages in order to assess the approach’s sensitivity. This letter demonstrated that the spatial downscaling approach performs well in the subhumid, semiarid, and in the arid bioclimatic stages, to a lesser extent. However, the approach seems to be sensitive and not adapted to the Saharan and humid stages.
Autors: Hicham Ezzine;Ahmed Bouziane;Driss Ouazar;Moulay Driss Hasnaoui;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1518 - 1521
Publisher: IEEE
 
» Sensitivity Prediction of Multiturn Fiber Coil-Based Fiber-Optic Flexural Disk Seismometer via Finite Element Method Analysis
Abstract:
This paper presents a method for predicting strain and sensitivity of a fiber-optic flexural disk seismometer (FODS) based on multiturn fiber coils (MTFC) via finite element method (FEM) analysis. FEM can be used to evaluate sensitivity by taking into account the strain distribution in MTFC. A sample MTFC-based FODS was fabricated according to simulation parameters; the experimental results of strain distribution and sensitivity were determined by Brillouin optical time-domain analysis and vibrator, respectively, which in turn can be used to confirm the correctness of the prediction model. The tested strain distribution of MTFC has the same characteristic with its simulation model; the predicted sensitivity of MTFC-based FODS is 6448.0 rad/g. Three sample sensors are fabricated and tested, which have a fabrication error of 7%. All FODS simulations were carried out in the COMSOL Multiphysics environment, which has significant potential for application as a tool of predicting the FODS sensitivity when designing or fabrication an MTFC-based FODS.
Autors: Feng Peng;Yan Lv;Hanyang Li;Shuaifei Tian;Wenjing Chen;Jun Yang;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:18, pages: 3870 - 3876
Publisher: IEEE
 
» Sensitivity Studies for Adaptive Coordinated Voltage Control: Scale and Similarity of Contingencies
Abstract:
The main framework of a new adaptive coordinated voltage control (ACVC) has been presented and published in our previous paper. ACVC is realized based on knowledge exploration from nondominated solution sets of multiobjective optimization. Knowledge is prepared and accumulated from offline training and online learning processes. This facilitates fast responses. An important basic work is to further study knowledge sensitivity to power system characteristics such that the efficiency of ACVC for various dynamics of power systems can be improved. A comparative study and discussion of power system scale, allocation of control devices, operational point variations, and severity of emergencies are presented in this paper. An improved form of knowledge is also proposed for ACVC based on these discussions. Numerical simulations on the IEEE 39-bus, 118-bus, and 300-bus power systems are performed for comparison and discussion.
Autors: Haomin Ma;David J. Hill;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3794 - 3802
Publisher: IEEE
 
» Sensor Array Optimization of Electronic Nose for Detection of Bacteria in Wound Infection
Abstract:
In order to identify the bacteria in wound infection, an electronic nose system with a sensor array of 34 sensors was designed. Eight kinds of samples were detected, i.e., culture medium, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and their mixture with different concentration. Using support vector machine as the classifier and without sensor array optimization, the recognition rate is up to 86.54%. To simplify the sensor array and improve the recognition rate for bacteria samples, Wilks’ lambda statistic (Wilks’ Λ-statistic), Mahalanobis distance, principal component analysis (PCA), linear discriminant analysis (LDA), and genetic algorithm are used to optimize the sensor array. It is shown that the sensor array optimization may be realized efficiently by these methods except PCA. After sensor array optimization by Wilks’ Λ-statistic and LDA, both of their recognition rates are the highest and up to 96.15%, while the numbers of sensors in optimized sensor arrays are 22 and 20, respectively. Under the limitation of ten sensors, the recognition rate optimized by Wilks’ Λ-statistic and LDA may still reach 95.19%.
Autors: Hao Sun;Fengchun Tian;Zhifang Liang;Tong Sun;Bin Yu;Simon X. Yang;Qinghua He;Longlong Zhang;Xiangmin Liu;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7350 - 7358
Publisher: IEEE
 
» Sensory-Based Failure Threshold Estimation for Remaining Useful Life Prediction
Abstract:
The rapid development of sensor and computing technology has created an unprecedented opportunity for condition monitoring and prognostic analysis in various manufacturing and healthcare industries. With the massive amount of sensor information available, important research efforts have been made in modeling the degradation signals of a unit and estimating its remaining useful life distribution. In particular, a unit is often considered to have failed when its degradation signal crosses a predefined failure threshold, which is assumed to be known a priori. Unfortunately, such a simplified assumption may not be valid in many applications given the stochastic nature of the underlying degradation mechanism. While there are some extended studies considering the variability in the estimated failure threshold via data-driven approaches, they focus on the failure threshold distribution of the population instead of that of an individual unit. Currently, the existing literature still lacks an effective approach to accurately estimate the failure threshold distribution of an operating unit based on its in-situ sensory data during condition monitoring. To fill this literature gap, this paper develops a convex quadratic formulation that combines the information from the degradation profiles of historical units and the in-situ sensory data from an operating unit to online estimate the failure threshold of this particular unit in the field. With a more accurate estimation of the failure threshold of the operating unit in real time, a better remaining useful life prediction is expected. Simulations as well as a case study involving a degradation dataset of aircraft turbine engines were used to numerically evaluate and compare the performance of the proposed methodology with the existing literature in the context of failure threshold estimation and remaining useful life prediction.
Autors: Abdallah Chehade;Scott Bonk;Kaibo Liu;
Appeared in: IEEE Transactions on Reliability
Publication date: Sep 2017, volume: 66, issue:3, pages: 939 - 949
Publisher: IEEE
 
» Separation of a Mixture of Simultaneous Dual-Tracer PET Signals: A Data-Driven Approach
Abstract:
In developing a signal separation algorithm, an obvious challenge relates to the ways in which the photon measurements from dual-tracer positron emission tomography (PET) are overlapped. Aside from this issue, the ill-conditioning and the noisy measures are still obstacles to achieve accurate and robust result. In this paper, we develop a novel approach from a data-driven perspective that separates dynamic dual-tracer PET signals into individual-tracer components explicitly with a simultaneous-injection single-scan. Our approach is divided into two phases: training and reconstruction. In the training phase, our proposed framework will learn the potential relationship of different frames for dynamic dual-tracer PET data. In the reconstruction phase, given the sinogram of a dual tracer, the PET activity map of an individual tracer can be obtained directly. Experiments on Monte Carlo simulation data sets are conducted as validation. The experimental results have demonstrated the superior performance of the proposed approach by comparing with the ground truth of the individual-tracer.
Autors: Dongsheng Ruan;Huafeng Liu;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Sep 2017, volume: 64, issue:9, pages: 2588 - 2597
Publisher: IEEE
 
» Separation of Overlapped Non-Stationary Signals by Ridge Path Regrouping and Intrinsic Chirp Component Decomposition
Abstract:
In some applications, it is necessary to analyze multi-component non-stationary signals whose components severely overlap in the time-frequency (T-F) domain. Separating those signal components is desired but very challenging for existing methods. To address this issue, we propose a novel non-parametric algorithm called ridge path regrouping (RPRG) to extract the instantaneous frequencies (IFs) of the overlapped components from a T-F representation (TFR). The RPRG first detects the ridges of a multi-component signal from a TFR and then extracts the desired IFs by regrouping the ridge curves according to their variation rates at the intersections. After the IFs are obtained, component separation is achieved by using the intrinsic chirp component decomposition (ICCD) method. Different from traditional T-F filter-based methods, the ICCD can accurately reconstruct overlapped components by using a joint-estimation scheme. Finally, applications of separating some simulated and experimental micro-Doppler signals are presented to show the effectiveness of the method.
Autors: Shiqian Chen;Xingjian Dong;Guanpei Xing;Zhike Peng;Wenming Zhang;Guang Meng;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5994 - 6005
Publisher: IEEE
 
» Sequence Control Verification of a Central Solenoid Converter for Nuclear Fusion Reactors by Using a Hardware-in-the-Loop
Abstract:
In this paper, verification of a four-series connected central solenoid (CS) converter sequence control of a nuclear fusion reactor to reduce reactive power by using a real-time digital simulator is described. The unit CS converter supplies voltage (±975 V) and current (±45 kA) to the CS superconducting magnets to induce current in plasma. The output voltage of the unit CS converter is limited because of the rated voltage of thyristor switches. However, the CS superconducting coil needs more operating output voltage. Thus, the CS converter must be connected in four series to provide the required operating output voltage. Adequate reactive power support is important to improve the electrical grid stability, because four-series connected CS converter generate large amounts of reactive power. However, other reactive compensators require high costs and a large area. Hence, sequence control is applied to the voltage control of the four-series connected CS converter in order to reduce the reactive power. The sequence controller calculates and transmits the individual voltage command to each unit CS converter according to the total voltage command via safe ring-type communication channel. To verify the feasibility of the proposed sequence control of four-series connected CS converter, five real Zynq-based controllers are assembled and a power system, including the four unit CS converters, is implemented in a real-time digital simulator for hardware-in-the-loop verification. Maximum reactive power is reduced by 16%, from 225 to 190 Mvar.
Autors: Hyunsik Jo;Hanju Cha;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 6864 - 6873
Publisher: IEEE
 
» Sequential Discrete Kalman Filter for Real-Time State Estimation in Power Distribution Systems: Theory and Implementation
Abstract:
This paper demonstrates the feasibility of implementing real-time state estimators for active distribution networks in field-programmable gate arrays (FPGAs) by presenting an operational prototype. The prototype is based on a linear state estimator that uses synchrophasor measurements from phasor measurement units. The underlying algorithm is the sequential discrete Kalman filter (SDKF), an equivalent formulation of the DKF for the case of uncorrelated measurement noise. In this regard, this paper formally proves the equivalence of SDKF and the DKF, and highlights the suitability of the SDKF for an FPGA implementation by means of a computational complexity analysis. The developed prototype is validated using a case study adapted from the IEEE 34-node distribution test feeder.
Autors: Andreas Martin Kettner;Mario Paolone;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2358 - 2370
Publisher: IEEE
 
» Setting the Standards for Engineering Education: A History [Scanning Our Past]
Abstract:
Who controls engineering education? And how has this control evolved over time? While some folks may presume that ABET has undisputed control over engineering degree programs in the United States, those familiar with ABET Engineering Criterion 2000’s origins know otherwise [1]. Moreover, history shows that the development of new standards in engineering education has always been a shared responsibility, with this responsibility being distributed in ways that reflect the broader fragmentation of the engineering profession. Still, the flurry of concern generated by ABET’s proposed new accreditation standard suggests that issues of control, or governance, will remain a common feature within U.S. engineering education [2], [3]. As we converge around ABET’s latest standard, we should use the broader lessons of history to understand how our recent conversations fit within a broader historical pattern, and use this to guide our future actions.
Autors: Atsushi Akera;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1834 - 1843
Publisher: IEEE
 
» SiC BJT Compact DC Model With Continuous- Temperature Scalability From 300 to 773 K
Abstract:
The first vertical bipolar intercompany (VBIC)-based compact dc model has been developed and verified for a low-voltage 4H-SiC bipolar junction transistor to continuously map a wide temperature range from 300 to 773 K. Temperature and doping dependent physical models for bandgap, incomplete ionization, carrier mobility, and lifetime have been taken into account to give physically meaningful fitting parameters for the compact model. Isothermal simulations using the default VBIC model are performed to extract key parameter sets from measured data at seven different temperature points. Then new temperature dependent equations for the key parameters are proposed and embedded in the default VBIC model. Consequently, a single set of model parameters at 300 K is used to achieve fitting over a wide temperature range from 300 to 773 K. This new model can be used for simulating circuits that require continuous description of device dc performance over a wide temperature range.
Autors: Ye Tian;Raheleh Hedayati;Carl-Mikael Zetterling;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3588 - 3594
Publisher: IEEE
 
» SigMA: Signaling Framework for Decentralized Network Management Applications
Abstract:
The management of network infrastructures has become increasingly complex over time, which is mainly attributed to the introduction of new functionality to support emerging services and applications. To address this important issue, research efforts in the last few years focused on developing software-defined networking solutions. While initial work proposed centralized architectures, their scalability limitations have led researchers to investigate a distributed control plane. Controller placement algorithms and mechanisms for building a logically centralized network view are some examples of challenges addressed in this context. A critical issue that requires specific attention concerns the communication between distributed entities involved in decision-making processes. To this end, we propose SigMA, a signaling framework that supports communication between the different entities of a decentralized management and control system. We also define the communication primitives and interfaces involved in such a decentralized environment. The benefits of SigMA are illustrated through three realistic network resource management use cases with different communication requirements. Based on simulation, we demonstrate the flexibility and extensibility of our solution in satisfying these requirements, thus effectively supporting advanced decentralized decision-making processes.
Autors: Dario Valocchi;Daphne Tuncer;Marinos Charalambides;Mauro Femminella;Gianluca Reali;George Pavlou;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 616 - 630
Publisher: IEEE
 
» Signal Multiplexing Techniques for GNSS: The Principle, Progress, and Challenges Within a Uniform Framework
Abstract:
Signal multiplexing techniques are those that enable the efficient transmission of multiple signals through a single modulator, up converter, power amplifier chain, and antenna aperture, without mutual interference. In the construction of new-generation global navigation satellite systems (GNSSs), signal multiplexing has encountered many challenges as the number of signals to be multiplexed increases and signal elements become more diverse and complex. In the past 15 years, many novel and advanced constant envelope multiplexing (CEM) techniques have been proposed. However, increased requirements for adaptability and flexibility of signal multiplexing techniques for future evolutional GNSSs have resulted in the need for further improvement in generalized CEM design theory. The uniform CEM mathematical framework and more general CEM design approaches can offer a good starting point to meet these challenges. In this article, we provide a comprehensive tutorial on the important concepts, recent advances, representative applications, and the remaining challenges of GNSS signal multiplexing techniques. To provide readers with a global overview of multiplexing techniques in GNSS and to foster new research ideas, a mathematical cornerstone and intrinsic conceptual relationship of assorted multiplexing techniques along with the high adaptability and high flexibility challenges of CEM design will be two key discussions.
Autors: Zheng Yao;Mingquan Lu;
Appeared in: IEEE Signal Processing Magazine
Publication date: Sep 2017, volume: 34, issue:5, pages: 16 - 26
Publisher: IEEE
 
» Signal Processing and Machine Learning for Mental Health Research and Clinical Applications [Perspectives]
Abstract:
Human behavior offers a window into the mind. When we observe someone's actions, we are constantly inferring his or her mental states-their beliefs, intents, and knowledge-a concept known as theory of mind. For example.
Autors: Daniel Bone;Chi-Chun Lee;Theodora Chaspari;James Gibson;Shrikanth Narayanan;
Appeared in: IEEE Signal Processing Magazine
Publication date: Sep 2017, volume: 34, issue:5, pages: 196 - 195
Publisher: IEEE
 
» Signal Processing for Gigabit-Rate Wireline Communications: An Overview of the State of the Art and Research Challenges
Abstract:
Signal processing played an important role in improving the quality of communications over copper cables in earlier digital subscriber line (DSL) technologies. Even more powerful signal processing techniques are required to enable a gigabit per second data rate in the upcoming fast access to subscriber terminals (G.fast.) standard. This new standard is different from its predecessors in many respects. In particular, G.fast will use a significantly higher bandwidth. At such a high bandwidth, crosstalk among different lines in a binder will reach unprecedented levels, which are beyond the capabilities of most efficient techniques for interference mitigation.
Autors: S.M. Zafaruddin;Itsik Bergel;Amir Leshem;
Appeared in: IEEE Signal Processing Magazine
Publication date: Sep 2017, volume: 34, issue:5, pages: 141 - 164
Publisher: IEEE
 
» Signal Structure-Based Authentication for Civil GNSSs: Recent Solutions and Perspectives
Abstract:
A key aspect to be considered in the design of new generations of global navigation satellite system (GNSS) signals and receivers is a proper partition between system and receiver contribution to the robustness against spoofing attacks. This article maps the current threats and vulnerabilities of GNSS receivers and presents a survey of recent defenses, focusing on cryptographic solutions suitable to authenticate civil signals. Future perspectives and trends are analyzed, with particular emphasis on spreading code authentication techniques, considered as a key innovation for the next generation of civil GNSS signals. An assessment of the robustness and feasibility of the various presented solutions is also provided, analyzing in particular the impact on both current and future receivers.
Autors: Davide Margaria;Beatrice Motella;Marco Anghileri;Jean-Jacques Floch;Ignacio Fernandez-Hernandez;Matteo Paonni;
Appeared in: IEEE Signal Processing Magazine
Publication date: Sep 2017, volume: 34, issue:5, pages: 27 - 37
Publisher: IEEE
 
» Signal-Based Sensor Fault Detection and Isolation for PMSG in Wind Energy Conversion Systems
Abstract:
This paper presents a fault detection and isolation system for additive and multiplicative faults for current and voltage measurements of a controlled wind energy conversion system (WECS). The method is based on an observer scheme, comprised of a time-varying Kalman filter and a maximum-shift strategy, to generate new residuals capable of detecting all fault types especially multiplicative ones with low gains. The detection system has been experimentally validated on a WECS driven by a permanent magnet synchronous generator, and experimental results have proved its effectiveness.
Autors: Karim Beddek;Adel Merabet;Mohamed Kesraoui;Aman A. Tanvir;Rachid Beguenane;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2403 - 2412
Publisher: IEEE
 
» Significant Wave Height Measured by Coherent X-Band Radar
Abstract:
Significant wave height is one of the most important parameters for characterizing ocean waves and essential for coastal protection, shipping, as well as off shore industry operations. Within this paper, a robust method is introduced for retrieving significant wave heights from Doppler speed measurements acquired with a coherent-on-receive marine radar. The Doppler velocity is caused by the surface scattering in the line of site of the radar. To a huge extent its periodic component is induced by the orbital motions associated with surface waves. The proposed methodology is based on linear wave theory, accounts for projection effects caused by the fixed antenna look direction, and was applied to a coherent-on-receive radar operating at X-band with vertical polarization in transmit and receive. To show the overall performance of the method, a data set consisting of approximately 100 days of radar measurements was analyzed and used to retrieve significant wave heights. Comparisons to wave measurements collected by a wave rider buoy resulted in a root-mean–square (rms) error of 0.21 m and a bias of 0 m without any calibration parameters needed. To further improve the accuracy of significant wave height, a calibration factor needs to be accounted for, which improves the rms error to 0.15 m with a negligible bias of −0.01 m.
Autors: Ruben Carrasco;Jochen Horstmann;Jörg Seemann;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 5355 - 5365
Publisher: IEEE
 
» Silo and Tank Vision: Applica?tions, Challenges, and Technical Solutions for Radar Measurement of Liquids and Bulk Solids in Tanks and Silos
Abstract:
In today's industrialized world, the handling of raw materials and goods is an essential part of the supply chain. Liquids-for example water, oil, chemicals, pharmaceutical products, and liquefied gases-are stored in tanks. Bulk solids, on the other hand, are stored in silos and cover a very large variety of materials. Examples include finely granulated substances (grains, powders, sand, plastic pellets, and so forth) and also very rough materials like stones, coal, and others. The operator of a storage system is, in either case, interested in measuring the filling volume to be able to plan removal and refilling-which is important to ensure the continuous production and delivery of materials on schedule.
Autors: Michael Vogt;Michael Gerding;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 38 - 51
Publisher: IEEE
 
» Simplified Approach to Evaluate the Combined Uncertainty in Measurement Instruments for Power Systems
Abstract:
This paper presents the study of the propagation of the effects of uncertainties in a typical measurement system for modern power networks. Nowadays there is a strong demand from the electricity industry of simple and ready-to-use solutions for calculating uncertainty in such “new” measurement systems. To this purpose a simplified approach is presented whose results are shown to be in good agreement with those provided by conventional but more complex methods. Two applications, rather simple but very common, are considered in this paper. In the first one, the measurement of a voltage phasor is considered and the measurement chain is made by an low power instrument transformer (LPIT) and a converter used for adapting the level of signals from the LPIT to the inputs of intelligent electronic device. The second application deals with the measurement of active power of a system made by a low power voltage transformer (LPVT), a low power current transformer and a powermeter.
Autors: Alessandro Mingotti;Lorenzo Peretto;Roberto Tinarelli;Kenan Yiğit;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2258 - 2265
Publisher: IEEE
 
» Simplified Method for Log-Likelihood Ratio Approximation in High-Order Modulations Based on the Voronoi Decomposition
Abstract:
In modern communication systems, high-order modulation schemes have been widely employed to improve the spectral efficiency. In this context, soft decision methods are usually preferred, due to their superior performance over hard decisions. Soft decoders use metrics such as the log-likelihood ratios (LLRs) to measure the reliability of their decisions. Typically, the complexity of the exact channel LLR calculation increases exponentially with the modulation order of the system. The most well-known LLR approximation, the Max-Log-MAP symbol-to-bit demapper, still demands a large number of operations. In this paper, we present a novel simplified scheme that greatly reduces the complexity of the LLR demapper at high-order PSK and APSK modulations compared to the Max-Log-MAP soft-demapper. Moreover, it is shown that the proposed method has a negligible overall system performance loss compared to the same method.
Autors: Vanessa B. Olivatto;Renato R. Lopes;Eduardo R. de Lima;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Sep 2017, volume: 63, issue:3, pages: 583 - 589
Publisher: IEEE
 
» Simulated Measurements of the Magnetic Behavior of New Dual-Mode Nanosized Contrast Agents
Abstract:
Aim of this work was to perform simulated measurements of the magnetic behavior of a novel class of bimodal nanosized contrast agents (CAs), made of a silica core covered by smaller superparamagnetic nanoparticles (NPs) and designed to be detected through both ultrasound and magnetic resonance imaging (MRI), in order to compare their performance in terms of MRI signal enhancement with that of the superparamagnetic NPs alone. The considered bimodal nanocomposites consisted of 330-nm silica nanospheres covered by either superparamagnetic iron oxide NPs or dumbbell-like FePt-IO nanocrystals. We simulated the MRI signal generated by each of the considered CAs during a brain venography in standard clinical conditions. Quantitative assessments of signal enhancement were carried out as a function of the main model parameters. The performed numerical simulations showed that the magnetic response of the novel nanocomposites was similar or better compared to that of the superparamagnetic NPs alone for echo times longer than 20 ms, leading to an easier detection of smaller vessels. Obtained results suggest that the bimodal NPs have an exciting potential for the development of innovative clinical protocols for multimodal imaging, combining quantitative measurements of cerebral blood flow and targeted molecular imaging of specific diseases.
Autors: Roberto Franchini;Ernesto Casciaro;Francesco Conversano;Aimè Lay-Ekuakille;Sergio Casciaro;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Sep 2017, volume: 16, issue:5, pages: 842 - 850
Publisher: IEEE
 
» Simulation Study of 4H-SiC UMOSFET Structure With p+-polySi/SiC Shielded Region
Abstract:
In this paper, we propose an enhanced efficiency 4H-SiC U-shaped trench-gate MOSFET (UMOSFET) structure. The proposed device structure takes an advantage of a p+-polySi/SiC shielded region to reduce the on-state specific resistance. We show that the heterojunction diode formed by the p+-polySi and the n-drift regions improves the body diode effect, and thereby, reduces the reverse recovery charge. Further, we illustrate through simulation results that in comparison with the traditional p+-SiC shielded UMOSFET, the proposed device structure provides a 56.5% improvement in the figure of merit (including the breakdown voltage and on-resistance), and a 35.7% and 55.5% reduction in specific on-resistance and reverse recovery charge, respectively.
Autors: Ying Wang;Ya-Chao Ma;Yue Hao;Yue Hu;Gaofeng Wang;Fei Cao;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Sep 2017, volume: 64, issue:9, pages: 3719 - 3724
Publisher: IEEE
 
» Simulation Study of an Ultrasound Retinal Prosthesis With a Novel Contact-Lens Array for Noninvasive Retinal Stimulation
Abstract:
Millions of people around the world suffer from varying degrees of vision loss (including complete blindness) because of retinal degenerative diseases. Artificial retinal prosthesis, which is usually based on electrical neurostimulation, is the most advanced technology for different types of retinal degeneration. However, this technology involves placing a device into the eyeball, and such a highly invasive procedure is inevitably highly risk and expensive. Ultrasound has been demonstrated to be a promising technology for noninvasive neurostimulation, making it possible to stimulate the retina and induce action potentials similar to those elicited by light stimulation. However, the technology of ultrasound retinal stimulation still requires considerable developments before it could be applied clinically. This paper proposes a novel contact-lens array transducer for use in an ultrasound retinal prosthesis (USRP). The transducer was designed in the shape of a contact lens so as to facilitate acoustic coupling with the eye liquid. The key parameters of the ultrasound transducer were simulated, and results are presented that indicate the achievement of 2-D pattern generation and that the proposed contact-lens array is suitable for multiple-focus neurostimulation, and can be used in a USRP.
Autors: Mengdi Gao;Yanyan Yu;Huixia Zhao;Guofeng Li;Hongyang Jiang;Congzhi Wang;Feiyan Cai;Leanne Lai-Hang Chan;Bernard Chiu;Wei Qian;Weibao Qiu;Hairong Zheng;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Sep 2017, volume: 25, issue:9, pages: 1605 - 1611
Publisher: IEEE
 
» Simultaneous Cost and QoS Optimization for Cloud Resource Allocation
Abstract:
Cloud computing is a new era of computing that offers resources and services for Web applications. Selection of optimal cloud resources is the main goal in cloud resource allocation. Sometimes, customers pay more than required since cloud providers’ pricing strategy is designed for the interest of the providers. Nonetheless, cloud customers are interested in selecting cloud resources to meet their quality of service (QoS) requirements. Thus, for the interest of both providers and customers, it is vital to balance the two conflicting objectives of deployment cost and QoS performance. In this paper, we present a cost-effective and runtime friendly algorithm that minimizes the deployment cost while meeting the QoS performance requirements. In other words, the algorithm offers an optimal choice, from customers’ point of view, for deploying a Web application in cloud environment. The multi-objective optimization algorithm minimizes cost and maximizes QoS performance simultaneously. The proposed algorithm is verified by a series of experiments on different workload scenarios deployed in two distinct cloud providers. The results show that the proposed algorithm finds the optimal combination of cloud resources that provides a balanced trade-off between deployment cost and QoS performance in relatively low runtime.
Autors: Seyedehmehrnaz Mireslami;Logan Rakai;Behrouz Homayoun Far;Mea Wang;
Appeared in: IEEE Transactions on Network and Service Management
Publication date: Sep 2017, volume: 14, issue:3, pages: 676 - 689
Publisher: IEEE
 
» Simultaneous Estimation of Electromechanical Modes and Forced Oscillations
Abstract:
Over the past several years, great strides have been made in the effort to monitor the small-signal stability of power systems. These efforts focus on estimating electromechanical modes, which are a property of the system that dictate how generators in different parts of the system exchange energy. Though the algorithms designed for this task are powerful and important for reliable operation of the power system, they are susceptible to severe bias when forced oscillations are present in the system. Forced oscillations are fundamentally different from electromechanical oscillations in that they are the result of a rogue input to the system, rather than a property of the system itself. To address the presence of forced oscillations, the frequently used AutoRegressive Moving Average (ARMA) model is adapted to include sinusoidal inputs, resulting in the AutoRegressive Moving Average plus Sinusoid (ARMA+S) model. From this model, a new Two-Stage Least Squares algorithm is derived to incorporate the forced oscillations, thereby enabling the simultaneous estimation of the electromechanical modes and the amplitude and phase of the forced oscillations. The method is validated using simulated power system data as well as data obtained from the western North American power system and Eastern Interconnection.
Autors: Jim Follum;John W. Pierre;Russell Martin;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3958 - 3967
Publisher: IEEE
 
» Simultaneous Sensing and Transmission for Cognitive Radios With Imperfect Signal Cancellation
Abstract:
In conventional cognitive radio systems, the secondary user employs a “listen-before-talk” paradigm, where it senses if the primary user is active or idle, before it decides to access the licensed spectrum. However, this method faces challenges, with the most important one being the reduction of the secondary user’s throughput, as no data transmission takes place during the sensing period. In this context, the idea of simultaneous spectrum sensing and data transmission is proposed. This paper studies a system model where this concept is obtained through the collaboration of the secondary transmitter with the secondary receiver. First, the secondary receiver decodes the signal from the secondary transmitter, removes it from the total received signal, and then carries out spectrum sensing in the remaining signal in order to determine the presence/absence of the primary user. Different from the existing literature, this paper considers the imperfect signal cancellation, evaluating how the decoding errors affect the sensing reliability, and derives the analytical expressions for the probability of false alarm. Finally, numerical results are presented illustrating the accuracy of the proposed analysis.
Autors: Christos Politis;Sina Maleki;Christos G. Tsinos;Konstantinos P. Liolis;Symeon Chatzinotas;Björn Ottersten;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5599 - 5615
Publisher: IEEE
 
» Simultaneous Wireless Information and Power Transfer for Downlink Multi-User Massive Antenna-Array Systems
Abstract:
We propose a simultaneous wireless information and power transfer scheme based on the power-splitting technique for the downlink of multi-user massive antenna-array systems. The base station (BS) can transmit both the wireless energy and information simultaneously to the user equipments (UEs). Using the harvested energy, each UE can transmit its pilot signal to the BS for the downlink channel estimation by exploiting the channel reciprocity of the time division duplexing system. When the antenna scale is large enough, the ergodic achievable rates of UEs are derived in closed-form. To maximize the minimum achievable rate among all the UEs, an iterative algorithm with low-complexity is proposed to jointly optimize the power allocation coefficients of the BS and the power-splitting ratios of the UEs. In each iteration of the proposed algorithm, the optimal power-splitting ratios can be determined according to the closed-form expressions for a given power allocation coefficient. The convergency, optimality, and complexity of our proposed algorithm are analyzed theoretically. The equal power allocation is shown to be optimal when the transmit power of BS is large enough. Furthermore, the optimal number of antennas is determined to maximize the energy efficiency. Simulation results are provided to validate our closed-form approximations and verify the efficiency of our proposed algorithm.
Autors: Xinhua Wang;Chao Zhai;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 4039 - 4048
Publisher: IEEE
 
» Single Sensor-Based MPPT of Partially Shaded PV System for Battery Charging by Using Cauchy and Gaussian Sine Cosine Optimization
Abstract:
This paper introduces a battery charging scheme from a solar photovoltaic (SPV) by using a single sensor-based maximum power point tracking (MPPT) strategy. Here, for quick and efficient tracking, a novel hybrid “Cauchy and Gaussian sine cosine optimization” (CGSCO) algorithm is proposed for MPPT, which is based on only a single current sensor. The main objective of the CGSCO algorithm is, maximum extraction of the power from SPV panel and efficiently charging the battery through maximizing the charging current of the battery. Due to the single sensor, the cost of the charging scheme is very low, as well as the algorithm complexity and computational burden are very less, so it can be easily implemented on the low-cost microcontroller. In this paper, a single current sensor-based battery charging scheme by CGSCO algorithm is tested on MATLAB simulator and verified on a developed hardware of the SPV system. The panel condition, with and without shaded as well as dynamic environmental condition (variable temperature and insolation), is considered during simulation as well as on hardware implementation. Moreover, the tracking ability is compared with the most recent state of the art techniques (Grey wolf optimization and Lagrange interpolation particle swarm optimization (LIPSO)) as well as compared with “CGSCO with the conventional dual (voltage and current) sensor-based MPPT scheme.” The efficient battery charging with quick MPPT by CGSCO algorithm w.r.t. all state of the art techniques as well as dual sensor-based MPPT scheme, in steady-state as well as in dynamic conditions meets the motive of the work.
Autors: Nishant Kumar;Ikhlaq Hussain;Bhim Singh;Bijaya Ketan Panigrahi;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 983 - 992
Publisher: IEEE
 
» Single-Event Multiple Transients in Conventional and Guard-Ring Hardened Inverter Chains Under Pulsed Laser and Heavy-Ion Irradiation
Abstract:
Single-event multiple transients (SEMTs) are investigated using an on-chip self-triggered circuit. Measured results for inverter chains of two layout designs, including a guard-ring design and a conventional design, are compared under pulsed laser and heavy-ion (Bi) irradiations. Pulsed laser exposures of different energies and Bi heavy-ion irradiation at different injection angles, including along the well direction and across the well direction, are found to produce SEMTs with different probabilities. The use of a guard-ring hardening technique is demonstrated to be very effective in reducing production of SEMTs for inverters without direct electrical connection. Charge sharing-induced SEMTs are found to have different pulsewidth distributions for angled ion incidence than normal ion or laser incidence.
Autors: Rongmei Chen;Fengqi Zhang;Wei Chen;Lili Ding;Xiaoqiang Guo;Chen Shen;Yinhong Luo;Wen Zhao;Lisang Zheng;Hongxia Guo;Yinong Liu;Daniel M. Fleetwood;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Sep 2017, volume: 64, issue:9, pages: 2511 - 2518
Publisher: IEEE
 
» Single-Event Transient Susceptibility Analysis and Evaluation Methodology for Clock Distribution Network in the Integrated Circuit Working in Real Time
Abstract:
With technology scaling down, the clock distribution networks (CDNs) in integrated circuits (ICs) are increasingly vulnerable to the single-event transient (SET). The SET on the CDN can even lead to failure of the whole circuit. Therefore, it is important to evaluate in terms of SET susceptibility of the CDN. In this paper, a novel SET susceptibility analysis and evaluation methodology for CDN in any circuit is proposed. This methodology allows a more precise analysis of SET propagation in the CDN and the CDN-SET-induced incorrect latching by electrical simulations of circuits working in real time. In our simulations, injection location of the SET traverses all clock nodes on the CDN, injection time of the SET is random, and pulsewidth of the SET is random in a certain range. This can reflect more realistically and accurately how an IC works in the aerospace. Using the proposed methodology, we analyzed and evaluated the SET susceptibility of the CDN in a case circuit. The simulation results include SET propagation along the clock paths, the CDN-SET-induced incorrect data latching in the sequential elements, relative sensitivity of the clock nodes and sequential elements, and contributions of radiation-induced clock race and radiation-induced clock jitter to soft error rate of the case circuit. These results can supply information for the design of an IC with high reliability. Moreover, our methodology can be used to analyze the factors influencing the SET sensitivity of CDN, and evaluate the hardening technique for CDN.
Autors: Peipei Hao;Shuming Chen;
Appeared in: IEEE Transactions on Device and Materials Reliability
Publication date: Sep 2017, volume: 17, issue:3, pages: 539 - 548
Publisher: IEEE
 
» Single-Layer Wideband Circularly Polarized High-Efficiency Reflectarray for Satellite Communications
Abstract:
This paper presents a single-layer circularly polarized reflectarray which achieves large bandwidth (BW) in terms of axial ratio (AR), gain, aperture efficiency (AE) and radiation pattern. By using a novel wideband S-shaped phasing element, an offset-fed reflectarray with 20° offset beam is designed based on the element angular rotation method. Theoretical analysis is given to analyze the effect of angular rotated elements on the performance of the reflectarray, which indicates that the AR BW of the reflectarray can exceed the AR BW of the feed horn. Furthermore, the influence of the differential spatial phase delay is analyzed quantitatively, and the performance of S-element-based reflectarrays with different aperture sizes are investigated and discussed. To verify these concepts, a 180 mm mm prototype with elements is fabricated and measured. The measured results confirm that the proposed reflectarray achieves a 68.5% 3-dB AR BW (7 to 14.3 GHz) and a 47.8% 3-dB gain BW (8.6 to 14 GHz). Moreover, the AE is larger than 50% in a 33% BW and larger than 30% in a 64% BW.
Autors: Long Zhang;Steven Gao;Qi Luo;Wenting Li;Yejun He;Qingxia Li;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4529 - 4538
Publisher: IEEE
 
» Single-Perturbation-Cycle Online Battery Impedance Spectrum Measurement Method With Closed-Loop Control of Power Converter
Abstract:
This paper presents a method for an online real-time electrochemical impedance spectroscopy (EIS) measurement of batteries using closed-loop control of power converter. Unlike the previously proposed method which allows the measurement of the ac impedance for a single frequency, the presented method in this paper allows for obtaining the EIS for a spectrum of frequencies by using the information included in a single perturbation cycle, or a few cycles of perturbation to obtain a more accurate EIS with a very wide frequency range. This will result in faster EIS measurement for a spectrum of frequencies and under the same battery operating conditions. The presented method utilizes closed-loop control operation for the EIS measurement functionality, which allows for better control of the output voltage and for upgrading the concept to be able to achieve no added perturbation ripple at the output of the system. The presented online real-time EIS measurement method utilizes a power converter with closed-loop control in order to create an output voltage step-function perturbation at a given frequency to generate battery voltage and current responses. By applying Fourier analysis to these responses, an EIS can be obtained for a range of frequencies equal or higher than the perturbation frequency of the step function. In addition, this paper presents a method to eliminate the added perturbation ripple when two or more power converters are used. The theoretical basis and experimental prototype results are provided to illustrate and validate the presented method.
Autors: Jaber A. Abu Qahouq;Zhiyong Xia;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7019 - 7029
Publisher: IEEE
 
» Single-Sided Field-Free Line Generator Magnet for Multi-Dimensional Magnetic Particle Imaging
Abstract:
Magnetic particle imaging (MPI) is an emerging medical imaging modality that is not yet adopted by clinical practice. Most of the working MPI prototypes, including commercial-grade research MPI scanners, utilize cylindrical bores that limit the access to the scanner and the imaging volume. Recently, a single-sided or an asymmetric device, which is based on a field-free point coplanar coil topology, has been introduced that shows promise in alleviating access constraint issues. In this paper, we present a simulation study of selection coils for a novel theoretical approach of designing a single-sided MPI device that has an advantage of a more sensitive field-free line topology.
Autors: Alexey Tonyushkin;
Appeared in: IEEE Transactions on Magnetics
Publication date: Sep 2017, volume: 53, issue:9, pages: 1 - 6
Publisher: IEEE
 
» Size Effect of Heat Transport in Microscale Gas Gap
Abstract:
Microscale gas gaps commonly exist in gas thermal conductance related microdevices, such as micro-hot-plate gas sensors and micro-Pirani vacuum gauges. In these devices, thermal conduction of the gas gaps is an important issue for their performance. Although simulations for size effect of the thermal conduction in microscale gas gaps have been carried out, experimental results are still rare. In this paper, four microhot plates that contain four gas gaps from 220 nm to 21 μm have been fabricated by a standard CMOS process and some additional post-CMOS processes. The thermal convection coefficient can be obtained as large as 1242 Wm2K-1 from the convection dominate 21-μm gap. The effective thermal conductivity of 220-nm gap is as low as 1.2 × 10-3 Wm-1K-1. Both of them indicate that size effect of gaseous heat transport is significant in such microscale devices.
Autors: Zhengxing Huang;Jiaqi Wang;Suyuan Bai;Jingwei Guan;Fengtian Zhang;Zhenan Tang;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7387 - 7391
Publisher: IEEE
 
» Slanted Tri-Gates for High-Voltage GaN Power Devices
Abstract:
In this letter, we introduce and demonstrate the concept of slanted tri-gates to enhance the breakdown voltage () in lateral GaN power devices. Conventionally, field plates (FPs) are used to enhance the by distributing more homogeneously the electric field near the gate electrode, which is mainly determined by their pinch-off voltage (). These FPs however rely on a vertical approach, in which is usually designed via the thickness of the FP oxide. On the other hand, the slanted tri-gate relies on a lateral design to tailor its , by simply changing the width () of their nanowires lithographically. Here, we demonstrate this concept for AlGaN/GaN-on-silicon MOSHEMTs resulting in an increase of ~500 V in compared with the counterpart planar devices. These devices presented a high of 1350 V with a small gate-to-drain separation () of , along with a record high-power figure-of-merit of 1.2 GW/cm among GaN-on-silicon lateral transistors.
Autors: Jun Ma;Elison Matioli;
Appeared in: IEEE Electron Device Letters
Publication date: Sep 2017, volume: 38, issue:9, pages: 1305 - 1308
Publisher: IEEE
 
» Sliding Mode Control of Discrete-Time Switched Systems with Repeated Scalar Nonlinearities
Abstract:
This note studies the design of sliding mode control (SMC) for discrete-time hybrid stochastic switched systems with repeated scalar nonlinearities. The weighed gain performance is considered for the system dynamics to optimize its transient state performance. First, sufficient conditions are given to guarantee the corresponding system is exponentially stable while achieving a desired weighed performance. A new switching surface function is constructed by the average dwell time technique and the positive diagonally dominant Lyapunov functional method to further reduce the conservativeness induced by the repeated scalar nonlinearity. Then, the corresponding sliding mode dynamics are obtained and the solvability condition for the desired switching surface function is derived. Furthermore, the synthesis of the proposed SMC law is proposed to force the resulting closed-loop system trajectories onto the pre-specified sliding mode region with a desired level of accuracy. Finally, the feasibility and the effectiveness of the presented new design techniques are illustrated by examples and simulations.
Autors: Xiaojie Su;Xinxin Liu;Peng Shi;Rongni Yang;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4604 - 4610
Publisher: IEEE
 
» Slow-Wave Propagation Properties of Substrate Integrated Waveguide Based on Anisotropic Artificial Material
Abstract:
In this paper, an inductor-loaded slow-wave substrate integrated waveguide (SIW) is presented and studied. The proposed structure features a number of unique propagation properties. First of all, the inductance value imposed along the transverse direction will affect the phase velocity and cutoff frequency of the waveguide simultaneously. Second, the inductance value in the longitudinal propagating direction will only affect the phase velocity but make no difference on the cutoff frequency. Based on the aforementioned characteristics, the size of structure could be controlled by separately tuning the loaded inductor along the transverse direction and longitudinal propagating direction. More importantly, it is released on the interrelationship between the phase velocity and cutoff frequency in the proposed guiding-wave structure. The feature will be beneficial to the design of leaky-wave antenna and matching circuits for SIW circuits. Finally, experimental results demonstrate that with the increasing of loaded inductance, a reduction of 35% in cutoff frequency is achieved compared with the conventional SIW counterpart. The phase velocity is also reduced by 35% with the increasing of the loaded inductor, which contributes to a miniaturized longitudinal dimension for a given electrical length.
Autors: Haiyan Jin;Yuliang Zhou;Yong Mao Huang;Ke Wu;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4676 - 4683
Publisher: IEEE
 
» Small Width, Low Distortions: Quantized Random Embeddings of Low-Complexity Sets
Abstract:
Under which conditions and with which distortions can we preserve the pairwise distances of low-complexity vectors, e.g., for structured sets, such as the set of sparse vectors or the one of low-rank matrices, when these are mapped (or embedded) in a finite set of vectors? This work addresses this general question through the specific use of a quantized and dithered random linear mapping, which combines, in the following order, a sub-Gaussian random projection in of vectors in , a random translation, or dither, of the projected vectors, and a uniform scalar quantizer of resolution applied componentwise. Thanks to this quantized mapping, we are first able to show that, with high probability, an embedding of a bounded set in can be achieved when distances in the quantized and in the original domains are measured with the - and -norm, respectively, and provided the number of quantized observations is large before the square of the “Gaussian mean width” of . In this case, we show that the embedding is actually quasi-isometric and only suffers from both multiplicative and - dditive distortions whose magnitudes decrease as for general sets, and as for structured set, when increases. Second, when one is only interested in characterizing the maximal distance separating two elements of mapped to the same quantized vector, i.e., the “consistency width” of the mapping, we show that for a similar number of measurements and with high probability, this width decays as for general sets and as for structured ones when increases. Finally, as an important aspect of this paper, we also establish how the non-Gaussianity of sub-Gaussian random projections inserted in the quantized mapping (e.g., for Bernoulli random matrices) impacts the class of vectors that can be embedded or whose consistency width provably decays when increases.
Autors: Laurent Jacques;
Appeared in: IEEE Transactions on Information Theory
Publication date: Sep 2017, volume: 63, issue:9, pages: 5477 - 5495
Publisher: IEEE
 
» Smart Energy-Efficient Clock Synthesizer for Duty-Cycled Sensor SoCs in 65 nm/28nm CMOS
Abstract:
Duty-cycled low-rate Internet-of-things (IoT) sensors are employed in diverse applications, requiring configurable and energy-efficient on-chip and on-demand clock synthesis. We present an all-digital frequency-locked loop (AD-FLL) capable of generating an accurate clock selectively in stand-alone operation or locked to a 32kHz reference. We report measurement results of two prototypes in 65nm and 28nm CMOS offering a configurable clock multiplication factor of up to 32 786, resulting in a wide tuning-range from a few MHz to 2.4GHz and 1.6GHz, respectively. The challenges of slow start-up and deterministic jitter are addressed by a fast hybrid-mode start-up procedure and by various jitter reduction modes. We also introduce the concept of Transient Clocking that leverages the capabilities of the proposed AD-FLL to make a system operational after cold-start or wake-up before the supply voltage has stabilized. We study two application examples that highlight the versatility of the concept in IoT applications and show its potential to amortize the time and energy cost of typical system start-up tasks, like state-restoration or wake-up event classification.
Autors: David E. Bellasi;Luca Benini;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Sep 2017, volume: 64, issue:9, pages: 2322 - 2333
Publisher: IEEE
 
» Smart Grid on Chip: Work Load-Balanced On-Chip Power Delivery
Abstract:
In this paper, a dynamic on-chip power delivery system for chip multiprocessors (CMPs) is proposed, analogous to the smart grid deployed for large-scale energy distribution. The system includes underprovisioned on-chip voltage regulators (VRs) interconnected through a switch network. The peak current rating of the VRs is selected to meet only the average current demand of the cores. A real-time load-balancing algorithm is developed to reconfigure the power delivery network (PDN) by combining the output of multiple VRs when the workload demand exceeds the peak current rating of a single regulator. An operating system level task scheduling heuristic distributes the workloads on the cores such that the required reconfiguration of the PDN is minimized. Simulation results for the proposed power delivery system indicate up to a 44% reduction in the energy consumption of the CMP. In addition, the on-chip footprint of the PDN, including the on-chip VRs and the switching network, is reduced by at least 23%. The proposed cross-layer power management technique is an optimum solution for power-constrained many-core architectures implemented in advanced technology nodes.
Autors: Divya Pathak;Houman Homayoun;Ioannis Savidis;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Sep 2017, volume: 25, issue:9, pages: 2538 - 2551
Publisher: IEEE
 
» Smart Test Strips: Next-Generation Inkjet-Printed Wireless Comprehensive Liquid Sensing Platforms
Abstract:
By combining radio-frequency identification (RFID) and paper-microfluidics technologies, a low-cost first-of-its-kind platform for comprehensive liquid sensing, i.e., the “smart test strip,” is presented, which enables portable wireless real-time liquid sensing with handhold devices (e.g., cell phones), and integration of various multifunctional electrical and chemical sensors, for numerous Lab-on-Chip applications, including manufacturing control, environmental monitoring, and point-of-care medical diagnostics. The fabrication of RFID tags and two types of microfluidics are accomplished by a single inkjet-printing process in a cost-effective environmental-friendly additive manufacturing approach, which makes possible the production of disposable, lightweight, and flexible sensing platforms. Taking advantage of the proposed smart test strips platforms, we demonstrate two proof-of-concept high-performance electrical sensors based on interdigitated electrode topologies: a resistivity-based sensor with a 1782 /( *m) sensitivity; nevertheless, the proposed permittivity-based sensor with a 15%/ sensitivity, but the proposed integrated wireless platform, can facilitate the integration of even more chemical and electrical sensors. In addition, two on-strip antenna prototypes have been designed, optimized, and tested to work at 2.4 GHz and 13.56 MHz, respectively. Furthermore, the wireless interrogation of a complete proof-of-concept smart test strip is presented, which shows an excellent sensing resolution of 1.33 over the range of 0–1371 $\Omega$.
Autors: Wenjing Su;Manos M. Tentzeris;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Sep 2017, volume: 64, issue:9, pages: 7359 - 7367
Publisher: IEEE
 
» Smart Textile Based on 12 Fiber Bragg Gratings Array for Vital Signs Monitoring
Abstract:
Over the last decades, wearable systems have gained interest for vital signs monitoring. Among several technologies, fiber Bragg grating (FBG) sensors are becoming popular for some advantages, such as high sensitivity, magnetic resonance compatibility, and the capability of performing distributed measurements. The aim of this paper is twofold: the description of the design and the fabrication of a smart textile based on an array of 12 FBGs; its feasibility assessment for monitoring respiratory parameters (i.e., respiratory rate, respiratory period, and inspiratory and expiratory periods) and heart rate on healthy volunteers in two positions (standing and supine). The increased number of FBGs embedded in this system with respect to previous developed prototypes aims at improving its accuracy in the estimation of the mentioned parameters. Future testing will be performed to investigate if the proposed solution allows improving the measurements of respiratory volumes exchanges and in new scenarios (e.g., sports medicine, including walking, running, and cycling activities).
Autors: Daniela Lo Presti;Carlo Massaroni;Domenico Formica;Paola Saccomandi;Francesco Giurazza;Michele Arturo Caponero;Emiliano Schena;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 6037 - 6043
Publisher: IEEE
 
» Smartphone-Based Adaptive Driving Maneuver Detection: A Large-Scale Evaluation Study
Abstract:
The proliferation of connected mobile devices together with advances in their sensing capacity has enabled a new distributed telematics platform. In particular, smartphones can be used as driving sensors to identify individual driver behavior and risky maneuvers. However, in order to estimate driver behavior with smartphones, the system must deal with different vehicle characteristics. This is the main limitation of existing sensing platforms, which are principally based on fixed thresholds for different sensing parameters. In this paper, we propose an adaptive driving maneuver detection mechanism that iteratively builds a statistical model of the driver, vehicle, and smartphone combination using a multivariate normal model. By means of experimentation over a test track and public roads, we first explore the capacity of different sensor input combinations to detect risky driving maneuvers, and we propose a training mechanism that adapts the profiling model to the vehicle, driver, and road topology. A large-scale evaluation study is conducted, showing that the model for maneuver detection and scoring is able to adapt to different drivers, vehicles, and road conditions.
Autors: German Castignani;Thierry Derrmann;Raphaël Frank;Thomas Engel;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Sep 2017, volume: 18, issue:9, pages: 2330 - 2339
Publisher: IEEE
 
» Smear and Fear by Numbers: Accounting, Information Technology, and Economic Control for the New Capitalism
Abstract:
The new capitalism may be described in terms of the innovation that enabled corporations to transform their demand and supply trade exchanges with their customers and suppliers through the Internet. This enabled (and better controlled) corporation's outsourcing of non-core and core activities, which naturally eliminated the need for capital resources. Furthermore, this permitted corporations to decapitalize and reduce considerably their "plant, property, and equipment" with all the associated long-term financing liabilities (long-term debt) and associated running and maintenance expenses. Innovation, outsourcing, and decapitalization represent the fundamental tenets of the new capitalism.
Autors: George Mickhail;
Appeared in: IEEE Technology and Society Magazine
Publication date: Sep 2017, volume: 36, issue:3, pages: 81 - 87
Publisher: IEEE
 
» Social Touch Technology: A Survey of Haptic Technology for Social Touch
Abstract:
This survey provides an overview of work on haptic technology for social touch. Social touch has been studied extensively in psychology and neuroscience. With the development of new technologies, it is now possible to engage in social touch at a distance or engage in social touch with artificial social agents. Social touch research has inspired research into technology mediated social touch, and this line of research has found effects similar to actual social touch. The importance of haptic stimulus qualities, multimodal cues, and contextual factors in technology mediated social touch is discussed. This survey is concluded by reflecting on the current state of research into social touch technology, and providing suggestions for future research and applications.
Autors: Gijs Huisman;
Appeared in: IEEE Transactions on Haptics
Publication date: Sep 2017, volume: 10, issue:3, pages: 391 - 408
Publisher: IEEE
 
» Socially-Sensitive Systems Design: Exploring Social Potential
Abstract:
In human society, individuals have long voluntarily organized themselves in groups, which embody, provide and/or facilitate a range of different social concepts, such as governance, justice, or mutual aid. These social groups vary in form, size, and permanence, but in different ways provide benefits to their members. In turn, members of these groups use their understanding and awareness of group expectations to help determine their own actions, to the benefit of themselves, each other, and the health of the group.
Autors: Kirstie Bellman;Jean Botev;Hanno Hildmann;Peter R. Lewis;Stephen Marsh;Jeremy Pitt;Ingo Scholtes;Sven Tomforde;
Appeared in: IEEE Technology and Society Magazine
Publication date: Sep 2017, volume: 36, issue:3, pages: 72 - 80
Publisher: IEEE
 
» Software Engineering of Safety-Critical Systems: Themes From Practitioners
Abstract:
This study addresses two important questions related to engineering of safety-critical software and software-intensive systems. The first question is: which software and software-intensive systems should be considered safety critical? The second question is: what processes, design practices, and tools have practitioners been using for building these systems? We answer these questions through an analysis of unstructured interviews with experienced engineers who self-describe as working on safety-critical systems. Then, a thematic analysis of these responses was conducted. The results of this study are intended to provide guidance to those building safety-critical systems and have implications on state engineering licensure boards, in the determination of legal liability, and in risk assessment for policymakers, corporate governors, and insurance executives.
Autors: Phillip A. Laplante;Joanna F. DeFranco;
Appeared in: IEEE Transactions on Reliability
Publication date: Sep 2017, volume: 66, issue:3, pages: 825 - 836
Publisher: IEEE
 
» Software Support Inside and Outside Solid-State Devices for High Performance and High Efficiency
Abstract:
In the past decade, flash memory has been in the spotlight across a variety of research communities from circuits to computer systems, and significant progress has been accomplished. This has enabled flash memory to become increasingly pervasive across the entire information technology infrastructure, from consumer electronics to cloud and supercomputing. This paper aims to provide a comprehensive survey on the important advancements and milestones in the domains across flash translation layer (FTL), operating systems, and applications. As the storage device hardware has been quickly commoditized, software becomes increasingly important to tap the potential of flash memory to its full extent. Therefore, a comprehensive survey with a focus on software aspects will be very valuable to the research community and industry. It is our hope that this survey paper will serve as a good reference for system practitioners and researchers.
Autors: Feng Chen;Tong Zhang;Xiaodong Zhang;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1650 - 1665
Publisher: IEEE
 
» Soil Moisture Active/Passive L-Band Microwave Radiometer Postlaunch Calibration
Abstract:
The Soil Moisture Active/Passive (SMAP) microwave radiometer is a fully polarimetric L-band radiometer flown on the SMAP satellite in a 6 a.m./6 p.m. sun-synchronous orbit at 685-km altitude. Since April 2015, the radiometer has been under calibration and validation to assess the quality of the radiometer L1B data product. Calibration methods, including the SMAP L1B TA2TB [from antenna temperature (TA) to the Earth’s surface brightness temperature (TB)] algorithm and TA forward models, are outlined, and validation approaches for calibration stability/quality are described in this paper, including future work. Results show that the current radiometer L1B data product (version 3) satisfies its requirements (uncertainty <1.3 K and calibration drift <0.4 K/months, and geolocation uncertainty <4 km) although there are biases in TA over cold sky and in TB comparing with the Soil Moisture and Ocean Salinity TB v620 data products.
Autors: Jinzheng Peng;Sidharth Misra;Jeffrey R. Piepmeier;Emmanuel P. Dinnat;Derek Hudson;David M. Le Vine;Giovanni De Amici;Priscilla N. Mohammed;Rajat Bindlish;Simon H. Yueh;Thomas Meissner;Thomas J. Jackson;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 5339 - 5354
Publisher: IEEE
 
» Soil Moisture Estimation by SAR in Alpine Fields Using Gaussian Process Regressor Trained by Model Simulations
Abstract:
In this paper, we address the problem of retrieving soil moisture over a grassland alpine area from Synthetic Aperture Radar (SAR) data using a statistical algorithm trained by simulations of a physical model. A time series of C-band VV-polarized Wide Swath images acquired by Envisat Advanced SAR (ASAR) in the snow-free periods of 2010 and 2011 was simulated using a discrete radiative transfer model (RTM). The test area was located in the Mazia valley, South Tyrol (Italy), where the main land types are meadows and pastures. Soil moisture was collected from five meteorological stations, two of which situated in meadows and the rest in pastures. The smallest and the highest RMSEs of the RTM simulations were 0.78 dB and 1.91 dB, respectively. After backscattering simulation, the top soil moisture was estimated using Gaussian Process Regression (GPR). GPR was trained with the backscatter model simulations (including terrain features) for 2010, and then used to predict moisture from radar observations acquired in 2011. The relative importance of different input features was also assessed. The RMSE of the predicted soil moisture for the largest training data set (including aspect as a terrain feature) was 5.6% Vol. and the corresponding correlation coefficient was 0.84.
Autors: Jelena Stamenkovic;Leila Guerriero;Paolo Ferrazzoli;Claudia Notarnicola;Felix Greifeneder;Jean-Philippe Thiran;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 4899 - 4912
Publisher: IEEE
 
» Soil Moisture Estimation Using Differential Radar Interferometry: Toward Separating Soil Moisture and Displacements
Abstract:
Differential interferometric synthetic aperture radar (DInSAR) measurements are sensitive to displacements, but also to soil moisture changes. Here, we analyze whether soil moisture can be estimated from three DInSAR observables without making any assumptions about its complex spatio-temporal dynamics, with the goal of removing its contribution from the displacement estimates. We find that the referenced DInSAR phase can be a suitable means to estimate time series up to an overall offset, as indicated by correlations with in situ measurements of 0.75–0.90 in two campaigns. However, the phase can only be referenced when no displacements (and atmospheric delays) occur or when they can be estimated reliably. We study the separability of displacements and using two additional DInSAR observables (closure phase and coherence magnitude) that are sensitive to but insensitive to displacements. However, our analyses show that neither contains enough information for this purpose, i.e., it is not possible to estimate uniquely. The soil moisture correction of the displacement estimates is hence ambiguous too. Their applicability is furthermore limited by their proneness to model misspecifications and decorrelation. Consequently, the separation of soil moisture changes and displacements using DInSAR observations alone is difficult in practice, and—like for mitigating tropospheric errors—additional data (e.g., external estimates) - r assumptions (e.g., spatio-temporal patterns) are required when the effects on the displacement estimates are comparable to the magnitude of the movements. This will be critical when soil moisture changes are correlated with the actual displacements.
Autors: Simon Zwieback;Scott Hensley;Irena Hajnsek;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Sep 2017, volume: 55, issue:9, pages: 5069 - 5083
Publisher: IEEE
 
» Solid-State Drives (SSDs) [Scanning the Issue]
Abstract:
The articles in this special issue cover all the most recent advances in the solid-state drive field from both hardware and software/firmware perspectives. If we look at the DRAM history, DRAM data access speeds have increased at a faster rate than HDDs. The gap in read and write performances between DRAM and HDD has widened in the last years, leaving an opportunity for a new intermediate memory/storage technology between HDDs and DRAM: nand Flash-based SSDs can fill this performance gap, thus profoundly changing the traditional memory hierarchy below the microprocessor.
Autors: Rino Micheloni;Piero Olivo;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1586 - 1588
Publisher: IEEE
 
» Solid-State Drives: Memory Driven Design Methodologies for Optimal Performance
Abstract:
Solid-state drives (SSDs) faced an astonishing development in the last few years, becoming the cornerstone to new paradigms and markets of the information technology, such as cloud computing and big data centers. So far, the SSD design approach has focused on the optimization of the Flash translation layer, the firmware devoted to fulfill the compatibility with traditional hard-disk drives. For hyperscaled SSDs this strategy is no longer valid since their performance and reliability are strictly linked to that of the NAND Flash memories that constitute the storage medium, in particular when the multilevel cell paradigm is considered. For this reason, the design flow must follow a bottom-up approach that, starting from an accurate knowledge of the time and use dependent reliability of the NAND Flash memories, selects the most appropriate error correction strategy to extend the SSD lifetime while reducing its performance degradation. Then, the design flow moves to that of the SSD controller and of the interface toward the host where the application is running. This paper will thoroughly discuss this bottom-up approach, and finally, it will show how it is possible to leverage new approaches, such as the software-defined storage system that, by exploiting a hardware/software codesign of the SSD controller architecture and of the host application, will be able to revolutionize the traditional computer/memory interaction.
Autors: Lorenzo Zuolo;Cristian Zambelli;Rino Micheloni;Piero Olivo;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1589 - 1608
Publisher: IEEE
 
» Solution of the Neumann Problem of Diffraction by a Strip Using the Wiener–Hopf Method: Short-Wave Asymptotic Solutions
Abstract:
Plane wave diffraction by a strip is considered by the Wiener–Hopf method and the simple short-wave asymptotic solutions are obtained. The Neumann boundary value problem is reduced to the solutions of the Fredholm integral equations of the second kind, and the exact solution in the form of the sum of infinite series has been found by the method of successive approximations. With the help of the saddle point method, the integral operators are calculated and the asymptotic solutions of system are found. The outcomes are compared with supra known asymptotic solutions taking into account tertiary diffraction. Quarternary diffraction was solved and the calculation methodology for the subsequent diffractions was shown.
Autors: Merey Sautbekova;Seil Sautbekov;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Sep 2017, volume: 65, issue:9, pages: 4797 - 4802
Publisher: IEEE
 
» Solving Multiperiod OPF Problems Using an AC-QP Algorithm Initialized With an SOCP Relaxation
Abstract:
Renewable generation and energy storage are playing an ever increasing role in power systems. Hence, there is a growing need for integrating these resources into the optimal power flow (OPF) problem. While storage devices are important for mitigating renewable variability, they introduce temporal coupling in the OPF constraints, resulting in a multiperiod OPF formulation. This paper explores a solution method for multiperiod AC OPF that combines a successive quadratic programming approach (AC-QP) with a second-order cone programming (SOCP) relaxation of the OPF problem. The SOCP relaxation's solution is used to initialize the AC-QP OPF algorithm. Additionally, the lower bound on the objective value obtained from the SOCP relaxation provides a measure of solution quality. This combined method is demonstrated on several test cases with up to 4259 nodes and a time horizon of eight time steps. A comparison of initialization schemes indicates that the SOCP-based approach offers improved convergence rate, execution time, and solution quality.
Autors: Jennifer F. Marley;Daniel K. Molzahn;Ian A. Hiskens;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3538 - 3548
Publisher: IEEE
 
» Spatial Disaggregation of Coarse Soil Moisture Data by Using High-Resolution Remotely Sensed Vegetation Products
Abstract:
A novel approach is presented to spatially disaggregate coarse soil moisture (SM) by only using remotely sensed vegetation index. The approach is based on the conditional relationship of vegetation with time-aggregated SM, allowing the coarse-scale SM to be disaggregated to the spatial resolution of the vegetation product. The method was applied to satellite-derived SM over January 2010–December 2011, using the high-resolution normalized difference vegetation index (NDVI). The results were evaluated against ground measurements during the two-year period over the contiguous United States and Spain, and also compared with an existing disaggregation method that also requires land surface temperature observations. It is shown that the proposed approach can provide fine-resolution SM with reasonable spatial variability.
Autors: Seokhyeon Kim;Keerthana Balakrishnan;Yi Liu;Fiona Johnson;Ashish Sharma;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1604 - 1608
Publisher: IEEE
 
» Spatial technology and social media in remote sensing: challenges and opportunities [point of view]
Abstract:
The convergence of remote sensing technologies with social media, coupled with advances in other location-aware technologies such as WiFi and smartphones, is moving us on a fast track to a situation in which we can readily know, at any time, where everybody and everything are located on the surface of the Earth, and to exploit the power of social media in different contexts. Remote sensing technology involves the use of systems and algorithms to record information about the surface of the Earth from a remote location [1]. Although reliable as a data source, remote sensing data may not always be available. However, these data can be complemented by other sources of data, such as geographic information systems (GIS) and social media [2], in order to address time-critical applications. For instance, relating publicly available social media information with remote sensing or GIS data can lead to a more efficient management of emergency response (which refers to applications in which real/near-real-time response is needed, such as natural disasters). Social media are now playing a more relevant role in our daily lives and provide a unique opportunity to gain valuable insight on information flow and social networking within the society. As a result, the integration of social media data with other consolidated technologies such as remote sensing or GIS is of great importance.
Autors: Jun Li;Jón Atli Benediktsson;Bing Zhang;Tao Yang;Antonio Plaza;
Appeared in: Proceedings of the IEEE
Publication date: Sep 2017, volume: 105, issue:9, pages: 1583 - 1585
Publisher: IEEE
 
» Spatially Adaptive Multi-Scale Optimization for Local Parameter Estimation in Cardiac Electrophysiology
Abstract:
To obtain a patient-specific cardiac electro-physiological (EP) model, it is important to estimate the 3-D distributed tissue properties of the myocardium. Ideally, the tissue property should be estimated at the resolution of the cardiac mesh. However, such high-dimensional estimation faces major challenges in identifiability and computation. Most existing works reduce this dimension by partitioning the cardiac mesh into a pre-defined set of segments. The resulting low-resolution solutions have a limited ability to represent the underlying heterogeneous tissue properties of varying sizes, locations, and distributions. In this paper, we present a novel framework that, going beyond a uniform low-resolution approach, is able to obtain a higher resolution estimation of tissue properties represented by spatially non-uniform resolution. This is achieved by two central elements: 1) a multi-scale coarse-to-fine optimization that facilitates higher resolution optimization using the lower resolution solution and 2) a spatially adaptive decision criterion that retains lower resolution in homogeneous tissue regions and allows higher resolution in heterogeneous tissue regions. The presented framework is evaluated in estimating the local tissue excitability properties of a cardiac EP model on both synthetic and real data experiments. Its performance is compared with optimization using pre-defined segments. Results demonstrate the feasibility of the presented framework to estimate local parameters and to reveal heterogeneous tissue properties at a higher resolution without using a high number of unknowns.
Autors: Jwala Dhamala;Hermenegild J. Arevalo;John Sapp;Milan Horacek;Katherine C. Wu;Natalia A. Trayanova;Linwei Wang;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Sep 2017, volume: 36, issue:9, pages: 1966 - 1978
Publisher: IEEE
 
» Spatio-Temporal Interference Correlation and Joint Coverage in Cellular Networks
Abstract:
This paper provides an analytical framework with foundations in stochastic geometry to characterize the spatio-temporal interference correlation as well as the joint coverage probability at two spatial locations in a cellular network. In particular, modeling the locations of cellular base stations (BSs) as a Poisson point process, we study interference correlation at two spatial locations and separated by a distance , when the user follows the closest BS association policy at both spatial locations and moves from to . With this user displacement, two scenarios can occur: i) the user is handed off to a new serving BS at , or ii) no handoff occurs and the user is served by the same BS at both locations. After providing intermediate results, such as probability of handoff and distance distributions of the serving BS at the two user locations, we use them to derive exact expressions for spatio-temporal interference correlation coefficient and joint coverage probability for any distance separation . We also study two different handoff strategies: i) handoff skipping, and ii) conventional handoffs, and derive the expressions of joint coverage probability for both strategies. The exact analysis is not straightforward and involves a careful treatment of the neighborhood of the two spatial locations and the resulting handoff scenarios. To provide analytic- l insights, we also provide easy-to-use expressions for two special cases: i) static user () and ii) highly mobile user (. As expected, our analysis shows that the interference correlation and joint coverage probability decrease with increasing , with corresponding to a completely uncorrelated scenario. Further design insights are also provided by studying the effect of few network/channel parameters, such as BS density and path loss on the interference correlation.
Autors: Shankar Krishnan;Harpreet S. Dhillon;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5659 - 5672
Publisher: IEEE
 
» Specific Detection of Antibiotics by Silicon-on-Chip Photonic Crystal Biosensor Arrays
Abstract:
Photonic crystal (PC) microcavities formed by 2-D air holes on silicon-on-insulator substrates were utilized as biosensors to detect antibiotics with high specificity. The antibiotic, gentamicin, with molecular weight of only 478 g/mol, was successfully detected via its binding to corresponding antibody pre-immobilized on the sensor surface. Detection range (in concentration) was extended by combining different types of PC biosensors on a single silicon chip, covering from 0.1 nM to 1 . Specificity of detection was also verified on the studied antibiotic.
Autors: Hai Yan;Chun-Ju Yang;Naimei Tang;Yi Zou;Swapnajit Chakravarty;Amanda Roth;Ray T. Chen;
Appeared in: IEEE Sensors Journal
Publication date: Sep 2017, volume: 17, issue:18, pages: 5915 - 5919
Publisher: IEEE
 
» Spectral and Energy Efficiency of Multi-Pair Massive MIMO Relay Network With Hybrid Processing
Abstract:
We consider a multi-pair massive multiple-input multiple-output relay network, where the relay is equipped with a large number, , of antennas, but driven by a far smaller number, , of radio-frequency (RF) chains. We assume that pairs of users are scheduled for simultaneous transmission, where satisfies . A hybrid signal processing scheme is presented for both uplink and downlink transmissions of the network. Analytical expressions of both spectral efficiency (SE) and energy efficiency (EE) are derived with respect to the RF chain number under imperfect channel estimation. It is revealed that, under the condition , the transmit power of each user and the relay can be, respectively, scaled down by and if pilot power scales with signal power, or they can be, respectively, scaled down by and if the pilot power is kept fixed, while maintaining an asymptotically unchanged SE. While regarding EE of the network, the optimal EE is shown to be achieved when , where , respectively, refer to the transmit power of the relay and each source terminal. We show that the network EE is a quasi-concave function with respect to the number of RF-chains which, therefore, admits a unique globally optimal choice of the RF-chain number. Numerical simulations are conducted to verify our observations.
Autors: Wei Xu;Jian Liu;Shi Jin;Xiaodai Dong;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3794 - 3809
Publisher: IEEE
 
» Spectral and Energy Efficiency of Uplink D2D Underlaid Massive MIMO Cellular Networks
Abstract:
One of the key 5G scenarios is that device-to-device (D2D) and massive multiple-input multiple-output (MIMO) will be co-existed. However, interference in the uplink D2D underlaid massive MIMO cellular networks needs to be coordinated, due to the vast cellular and D2D transmissions. To this end, this paper introduces a spatially dynamic power control solution for mitigating the cellular-to-D2D and D2D-to-cellular interference. In particular, the proposed D2D power control policy is rather flexible, including the special cases of no D2D links or using maximum transmit power. Under the considered power control, an analytical approach is developed to evaluate the spectral efficiency (SE) and energy efficiency (EE) in such networks. Thus, the exact expressions of SE for a cellular user or D2D transmitter are derived, which quantify the impacts of key system parameters, such as massive MIMO antennas and D2D density. Moreover, the D2D scale properties are obtained, which provide the sufficient conditions for achieving the anticipated SE. Numerical results corroborate our analysis and show that the proposed power control solution can efficiently mitigate interference between the cellular and the D2D tier. The results demonstrate that there exists the optimal D2D density for maximizing the area SE of D2D tier. In addition, the achievable EE of a cellular user can be comparable with that of a D2D user.
Autors: Anqi He;Lifeng Wang;Yue Chen;Kai-Kit Wong;Maged Elkashlan;
Appeared in: IEEE Transactions on Communications
Publication date: Sep 2017, volume: 65, issue:9, pages: 3780 - 3793
Publisher: IEEE
 
» Spectral Projector-Based Graph Fourier Transforms
Abstract:
This paper considers the definition of the graph Fourier transform (GFT) and of the spectral decomposition of graph signals. Current literature does not address the lack of unicity of the GFT. The GFT is the mapping from the signal set into its representation by a direct sum of irreducible shift invariant subspaces: 1) this decomposition may not be unique; and 2) there is freedom in the choice of basis for each component subspace. These issues are particularly relevant when the graph shift has repeated eigenvalues as is the case in many real-world applications; by ignoring them, there is no way of knowing if different researchers are using the same definition of the GFT and whether their results are comparable or not. The paper presents how to resolve the above degrees of freedom. We develop a quasi-coordinate free definition of the GFT and graph spectral decomposition of graph signals that we implement through oblique spectral projectors. We present properties of the GFT and of the spectral projectors and discuss a generalized Parseval's inequality. An illustrative example for a large real-world urban traffic dataset is provided.
Autors: Joya A. Deri;José M. F. Moura;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Sep 2017, volume: 11, issue:6, pages: 785 - 795
Publisher: IEEE
 
» Spectrum Allocation and Power Control for Non-Orthogonal Multiple Access in HetNets
Abstract:
In this paper, a novel resource allocation design is investigated for non-orthogonal multiple access (NOMA) enhanced heterogeneous networks (HetNets), where small cell base stations (SBSs) are capable of communicating with multiple small cell users (SCUs) via the NOMA protocol. With the aim of maximizing the sum rate of SCUs while taking the fairness issue into consideration, a joint problem of spectrum allocation and power control is formulated. In particular, the spectrum allocation problem is modeled as a many-to-one matching game with peer effects. We propose a novel algorithm where the SBSs and resource blocks interact to decide their desired allocation. The proposed algorithm is proved to converge to a two-sided exchange-stable matching. Furthermore, we introduce the concept of ‘exploration’ into the matching game for further improving the SCUs’ sum rate. The power control of each SBS is formulated as a non-convex problem, where the sequential convex programming is adopted to iteratively update the power allocation result by solving the approximate convex problem. The obtained solution is proved to satisfy the Karush-Kuhn–Tucker conditions. We unveil that: 1) the proposed algorithm closely approaches the optimal solution within a limited number of iterations; 2) the ‘exploration’ action is capable of further enhancing the performance of the matching algorithm; and 3) the developed NOMA-enhanced HetNets achieve a higher SCUs’ sum rate compared with the conventional OMA-based HetNets.
Autors: Jingjing Zhao;Yuanwei Liu;Kok Keong Chai;Arumugam Nallanathan;Yue Chen;Zhu Han;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5825 - 5837
Publisher: IEEE
 
» Specular Beamforming
Abstract:
Acoustically hard objects, such as bones, needles, or catheters, are poorly visualized in conventional ultrasound images. These objects behave like acoustic mirrors and reflect sound in specific directions. Soft tissue and diffusive reflectors scatter sound in a broad range of directions. Conventional delay-and-sum beamforming is based on the assumption of a purely scattering domain with relatively weak reflectivity. We present an adaptive beamforming technique that takes into account the physics of specular reflection. Patterns predicted by the law of reflection are detected across the pool of received data and used to enhance the visualization of specular energy. This technique can be applied to any synthetic imaging sequence. Here, it is applied to synthetic transmit aperture imaging. In vitro experiments show a clear improvement in target visibility and an increase of 30 to 60 dB in signal-to-noise ratio.
Autors: Alfonso Rodriguez-Molares;Ali Fatemi;Lasse Løvstakken;Hans Torp;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Sep 2017, volume: 64, issue:9, pages: 1285 - 1297
Publisher: IEEE
 
» SPIDER: Sizing-Priority-Based Application-Driven Memory for Mobile Video Applications
Abstract:
Recently, mobile devices such as smartphones and tablets have become the most important medium for delivering internet traffic, especially multimedia content, to end users. However, mobile embedded memory incurs large power consumption owing to the highly frequent access and extensive computation. This paper presents an sizing-priority-based application-driven memory (SPIDER) design methodology for low-power mobile video applications. We investigate the size dependent memory failure characteristics and effectively reduce the memory failure rate with low area overhead. Also, we develop a model for the influence of the memory failure on video output, connecting the hardware design process and application requirement. Based on this, we design the SPIDER algorithms for area-priority and quality-priority mobile video applications. During this process, we also consider the contribution of both Luma and Chroma to output quality, avoiding over-optimization issue. We also develop a hardware-based python-assisted SPIDER simulator to apply our proposed design in one leading edge video compression system, the H.264 decoder. Our simulation results in 45-nm CMOS technology show that SPIDER supports mobile videos successfully as voltage downs to 500 mV from 1 V, enabling over 70% power savings in memory arrays.
Autors: Na Gong;Seyed Alireza Pourbakhsh;Xiaowei Chen;Xin Wang;Dongliang Chen;Jinhui Wang;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Sep 2017, volume: 25, issue:9, pages: 2625 - 2634
Publisher: IEEE
 
» Spike-Like Blending Noise Attenuation Using Structural Low-Rank Decomposition
Abstract:
Spikelike noise is a common type of random noise existing in many geoscience and remote sensing data sets. The attenuation of spike-like noise has become extremely important recently, because it is the main bottleneck when processing the simultaneous source data that are generated from the modern seismic acquisition. In this letter, we propose a novel low-rank decomposition algorithm that is effective in rejecting the spike-like noise in the seismic data set. The specialty of the low-rank decomposition algorithm is that it is applied along the morphological direction of the seismic data sets with a prior knowledge of the morphology of the seismic data, which we call local slope. The seismic data are of much lower rank along the morphological direction than along the space direction. The morphology of the seismic data (local slope) is obtained via a robust plane-wave destruction method. We use two simulated field data examples to illustrate the algorithm workflow and its effective performance.
Autors: Yatong Zhou;Chaojun Shi;Hanming Chen;Jianyong Xie;Guoning Wu;Yangkang Chen;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1633 - 1637
Publisher: IEEE
 
» SRI-Immune Highly Sensitive Temperature Sensor of Long-Period Fiber Gratings in Ge–Sb–Se Chalcogenide Fibers
Abstract:
This work exhibits design and characteristic study of highly sensitive temperature sensors of long-period fiber gratings (LPFGs) in Ge–Sb–Se fibers. Temperature characterization of the designed LPFGs with different working modes, operating wavelengths, and surrounding refractive indices (SRI) were studied. Results showed that temperature sensitivity of the proposed Ge–Sb–Se LPFGs reached 0.5787 nm/ at 1.55 μm at the lowest LP02 cladding mode, which is approximately 12 times higher than silica LPFGs and 1.2 times higher than that of As–Se LPFGs. When grating period of the designed Ge–Sb–Se LPFG was selected at its dispersion-turning-point, temperature sensitivity reached a maximum absolute value of 24.715 nm/°C. Influences of operating wavelength and temperature sensitivity of these LPFGs on SRI are extremely weak due to relatively high refractive index of Ge–Sb–Se fiber, indicating that the designed Ge–Sb–Se LPFG temperature sensor possesses extremely strong sensing stability on SRI.
Autors: Dandan Yang;Peiqing Zhang;Jianghui Zeng;Xunsi Wang;Baoan Song;Shixun Dai;
Appeared in: Journal of Lightwave Technology
Publication date: Sep 2017, volume: 35, issue:18, pages: 3974 - 3979
Publisher: IEEE
 
» Stability Analysis of a PMSG-Based Large Offshore Wind Farm Connected to a VSC-HVDC
Abstract:
This paper presents modal analysis of a large offshore wind farm using permanent magnet synchronous generator (PMSG)-type wind turbines connected to a voltage source converter HVDC (VSC-HVDC). Multiple resonant frequencies are observed in the ac grid of offshore wind farms. Their control is crucial for the uninterrupted operation of the wind farm system. The characteristics of oscillatory modes are presented using modal analysis and participation factor analysis. Sensitivity of critical modes to wind turbine design parameters and their impact on closed loop stability of the system are discussed. A comparison between a full wind farm model and an aggregated model is presented to show differences in the characteristics of critical modes observed in the models, and implication of using the models for stability studies It is concluded that robust control design is important for reliable operation of the system.
Autors: Linash P. Kunjumuhammed;Bikash C. Pal;Robin Gupta;Kevin J. Dyke;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Sep 2017, volume: 32, issue:3, pages: 1166 - 1176
Publisher: IEEE
 
» Stability Analysis of Impulsive Stochastic Nonlinear Systems
Abstract:
This paper studies stochastic input-to-state stability and stochastic global stability for impulsive stochastic nonlinear systems. Using fixed dwell-time condition and Lyapunov-based approach, sufficient conditions are established for the stability properties. Two cases are studied: 1) the case that the continuous dynamics is stable and 2) the case that the impulsive effects are stable. Furthermore, the relations among different dwell-time conditions are studied. Finally, two examples are used to illustrate the developed theory.
Autors: Wei Ren;Junlin Xiong;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4791 - 4797
Publisher: IEEE
 
» Stability Analysis of Non-Foster Circuit Using Normalized Determinant Function
Abstract:
Non-Foster elements are highly desired to overcome the bandwidth limit of electrically small antennas, cloaking, and metamaterials. However, they are prone to be unstable and thus it is quite challenging to implement non-Foster circuits in practice. Hence a rigorous and effective method of analyzing the stability should always be the priority when designing a non-Foster network. This paper applies normalized determinant function to analyze the stability of non-Foster circuits. A floating-version negative capacitor based on Linvill’s negative impedance converter is taken as the example. Factors affecting the stability in the practical design are thoroughly investigated, including device parasitics, dc biasing, distributed transmission line in the layout and load impedance. Circuit parameters are substituted with practical values to reduce the complexity of calculation. Finally, experiments are conducted to verify the analysis.
Autors: Qi Tang;Hao Xin;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Sep 2017, volume: 65, issue:9, pages: 3269 - 3277
Publisher: IEEE
 
» Stability and Bifurcation of Delayed Fractional-Order Dual Congestion Control Algorithms
Abstract:
In this technical note, fractional-order congestion control systems are introduced for the first time. In comparison with the conventional integer-order dual congestion control algorithms, the fractional control algorithms are more accurate and versatile. Bifurcation theory in fractional-order differential equations is still an outstanding problem. Sufficient conditions for the occurrence of Hopf bifurcations are extended from integer-order dynamical systems to fractional-order cases. Then, these conditions are used to establish the existence of Hopf bifurcations for the delayed fractional-order model of dual congestion control algorithms proposed in this note. Finally, the onsets of bifurcations are identified, where Hopf bifurcations occur and a family of oscillations bifurcate from the equilibrium. Illustrative examples are also provided to demonstrate the theoretical results.
Autors: Min Xiao;Wei Xing Zheng;Guoping Jiang;Jinde Cao;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4819 - 4826
Publisher: IEEE
 
» Stabilization of Uncertain Discrete-Time Linear System With Limited Communication
Abstract:
This technical note proposes a procedure to control an uncertain discrete-time networked system using an aperiodic stabilizing input information. The system is primarily affected by the time-varying, norm bounded, mismatched parametric uncertainty. Aperiodic exchange of information is done due to bandwidth constraint of the communication network. An event-triggered based robust control strategy is adopted to reduce the effects of system uncertainty in such bandwidth constrained networks. In event-triggered control, the control input is computed and actuated at the system end only when a pre-specified event condition is violated. The robust control input is derived to stabilize the uncertain system by solving an optimal control problem based on a virtual nominal dynamics and a modified cost-functional. It is shown that the robust control law with aperiodic information ensures input-to-state stability (ISS) of the original system in the presence of mismatched uncertainty. Deriving the event-triggering condition for a discrete-time uncertain system and ensuring the stability of such system analytically are the key contributions of this technical note. A numerical example is given to prove the efficacy of the proposed event-based control algorithm over the conventional periodic one.
Autors: Niladri Sekhar Tripathy;I. N. Kar;Kolin Paul;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4727 - 4733
Publisher: IEEE
 
» Stabilizing Quantum States and Automatic Error Correction by Dissipation Control
Abstract:
In this technical note an extended scalability condition is proposed to achieve the ground-state stability for a class of multipartite quantum systems which may involve two-body interactions, and an explicit procedure to construct the dissipation control is presented. Moreover, we show that dissipation control can be used for automatic error correction in addition to stabilization. We demonstrate the stabilization and error correction of three-qubit repetition code states using dissipation control.
Autors: Yu Pan;Thien Nguyen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Sep 2017, volume: 62, issue:9, pages: 4625 - 4630
Publisher: IEEE
 
» Stacked Multilevel-Denoising Autoencoders: A New Representation Learning Approach for Wind Turbine Gearbox Fault Diagnosis
Abstract:
Currently, vibration analysis has been widely considered as an effective way to fulfill the fault diagnosis task of gearboxes in wind turbines (WTs). However, vibration signals are usually with abundant noise and characterized as nonlinearity and nonstationarity. Therefore, it is quite challenging to extract robust and useful fault features from complex vibration signals to achieve an accurate and reliable diagnosis. This paper proposes a novel feature representation learning approach, named stacked multilevel-denoising autoencoders (SMLDAEs), with the aim to learn robust and discriminative fault feature representations through a deep network architecture for diagnosis accuracy improvement. In our proposed approach, we design an MLD training scheme, which uses multiple noise levels to train AEs. It enables to learn more general and detailed fault feature patterns simultaneously at different scales from the complex frequency spectra of the raw vibration data, and therefore helps enhance the feature learning and fault diagnosis capability. Furthermore, SMLDAE-based fault diagnosis is performed with an unsupervised representation learning procedure followed by a supervised fine-tuning process with label information for classification. Our approach is evaluated by using the field vibration data collected from a self-designed WT gearbox test rig. The results show that our proposed approach learned more robust and discriminative fault feature representations and achieved the best diagnosis accuracy compared with the traditional approaches.
Autors: Guoqian Jiang;Haibo He;Ping Xie;Yufei Tang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2391 - 2402
Publisher: IEEE
 
» Staleness Bounds and Efficient Protocols for Dissemination of Global Channel State Information
Abstract:
This paper considers the problem of achieving global channel knowledge throughout a fully connected packetized wireless network with time-varying channels. While the value of channel state information at the transmitter (CSIT) is now well known, there are many scenarios in which it is helpful to have additional channel knowledge beyond conventional CSIT, e.g., cooperative communication systems. The overhead required for global CSI knowledge can be significant, particularly in time-varying channels where the quality of channel estimates is dominated by the “staleness” of the CSI. Nevertheless, the fundamental limits and feasibility of tracking global CSI throughout a network have not been sufficiently studied. This paper presents a framework for analyzing the staleness of protocols that estimate and disseminate CSI to all nodes in a fully connected network. Fundamental bounds on achievable staleness are derived, and efficient dissemination protocols are developed, which achieve these limits. The results provide engineering guidelines on the feasibility of tracking global CSI as a function of network size, the size and composition of the packets, packet error rate, and channel coherence time.
Autors: Andrew G. Klein;Shahab Farazi;Wenmin He;D. Richard Brown;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Sep 2017, volume: 16, issue:9, pages: 5732 - 5746
Publisher: IEEE
 
» State Estimation and Fusion in the Presence of Integrated Measurement
Abstract:
State estimation and fusion is studied using Kalman filter (KF) when a slow-rate integrated measurement is available. Integrated measurement is common in industrial processes, when a sample of material is gradually collected over some period of time and then sent to a laboratory for analysis. In this case, the laboratory measurement will reflect the material properties that have been integrated over the sampling period. The goal is to estimate the fast-rate value of states that evolve with time. A modified KF is proposed to execute state estimation using a slow-rate integrated measurement. Fusion of the slow-rate state estimate and other fast-rate measurements can improve the final state estimation of the process. The performance of the proposed method is demonstrated through both simulation and experimental study in a laboratory scale hybrid tank pilot plant.

Note to Practitioners—When a sample of material is sent to laboratory for analysis, a common practice is to gradually collect a small amount of material over a period of time in a container and send the collection to the laboratory at the end of the sampling period. In this case, the laboratory measures the average of the variable during that period of time. Experienced operators can use this measurement to operate the process. However, including this integrated slow rate measurement into the automatic process control and monitoring system is a challenging problem. In this paper, we mathematically formulate the estimation of the real-time value of a variable using integrated laboratory measurement. The estimation is also improved through fusion of this measurement and other conventional measurements. Laboratory experimental result illustrates the feasibility of the proposed method.

Autors: Alireza Fatehi;Biao Huang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Sep 2017, volume: 66, issue:9, pages: 2490 - 2499
Publisher: IEEE
 
» Static Analysis of Model Transformations
Abstract:
Model transformations are central to Model-Driven Engineering (MDE), where they are used to transform models between different languages; to refactor and simulate models; or to generate code from models. Thus, given their prominent role in MDE, practical methods helping in detecting errors in transformations and automate their verification are needed. In this paper, we present a method for the static analysis of ATL model transformations. The method aims at discovering typing and rule errors, like unresolved bindings, uninitialized features or rule conflicts. It relies on static analysis and type inference, and uses constraint solving to assert whether a source model triggering the execution of a given problematic statement can possibly exist. Our method is supported by a tool that integrates seamlessly with the ATL development environment. To evaluate the usefulness of our method, we have used it to analyse a public repository of ATL transformations. The high number of errors discovered shows that static analysis of ATL transformations is needed in practice. Moreover, we have measured the precision and recall of the method by considering a synthetic set of transformations obtained by mutation techniques, and comparing with random testing. The experiment shows good overall results in terms of false positives and negatives.
Autors: Jesús Sánchez Cuadrado;Esther Guerra;Juan de Lara;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Sep 2017, volume: 43, issue:9, pages: 868 - 897
Publisher: IEEE
 
» Static Output Feedback Frequency Stabilization of Time-Delay Power Systems With Coordinated Electric Vehicles State of Charge Control
Abstract:
In this paper, for the first time, electric vehicles are used for both the primary and secondary frequency controls to support power plants to rapidly suppress fluctuations in the system frequency due to load disturbances. Via networked control and wide-area communication infrastructures, multiple interval time-varying delays exist in the communication channels between the control center, power plant, and an aggregation of electric vehicles. By coordinating batteries’ state of charge control, the behaviors of the vehicle owners and the uncertainties imposed by the changes of the batteries’ state of charge are taken into consideration. A power system model incorporating multiple time-varying delays and uncertainties is first proposed. Then, a robust static output feedback frequency controller is designed to guarantee the resulting closed-loop system stable with an attenuation level. By utilizing a novel integral inequality, namely refined-Jensen inequality, and an improved reciprocally convex combination, the design conditions are formulated in terms of tractable linear matrix inequalities which can be efficiently solved by various computational tools. The effectiveness of the proposed control scheme is verified by extensive simulations.
Autors: Thanh Ngoc Pham;Saeid Nahavandi;Le Van Hien;Hieu Trinh;Kit Po Wong;
Appeared in: IEEE Transactions on Power Systems
Publication date: Sep 2017, volume: 32, issue:5, pages: 3862 - 3874
Publisher: IEEE
 
» Statistical Distribution of Through-Silicon via Cu Pumping
Abstract:
Cu pumping is defined as the irreversible extrusion of Cu from Cu-filled through-silicon vias (TSVs) exposed to high temperatures. The distribution of Cu pumping values over the TSVs of a single wafer has a large intrinsic spread. In previous publications both a lognormal distribution and a distribution of the maximum of two normal variables were used to fit experimental data. In this paper, these two types of statistical distribution are compared, showing that the maximum of two normal distributions provides a better fit, in particular at the right tail which is more significant for the potential reliability impact of Cu pumping. Also, it is shown how Cu pumping is determined by the network of random high angle grain boundaries in the Cu region near the TSV top, as an extension of a previous analysis which occurred at the TSV top surface only. This relation between Cu pumping and Cu microstructure provides a physical interpretation of the maximum of two normal distributions, based on the deformation mechanisms underlying Cu pumping.
Autors: Joke De Messemaeker;Philippe J. Roussel;Olalla Varela Pedreira;Tom Van der Donck;Stefaan Van Huylenbroeck;Eric Beyne;Ingrid De Wolf;Michele Stucchi;Kristof Croes;
Appeared in: IEEE Transactions on Device and Materials Reliability
Publication date: Sep 2017, volume: 17, issue:3, pages: 549 - 559
Publisher: IEEE
 
» Statistical Properties of Polarimetric Weather Radar Returns for Nonuniformly Filled Beams
Abstract:
An explicit expression for stochastic processes describing the dual-polarization weather radar echoes is presented. The probability distributions of the proposed model are defined in terms of the point values assumed by polarimetric and Doppler variables in the relevant radar sampling volume. The statistical properties of the model are discussed in order to verify its faithfulness as representative of real radar signals. The discussion considers the most general situation, i.e., it is not related to specific hydrometeor distributions or beam filling conditions.
Autors: Stefano Cavallaro;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Sep 2017, volume: 14, issue:9, pages: 1584 - 1588
Publisher: IEEE
 
» Stay Current and Earn Continuing Education Credits [Education News]
Abstract:
Presents a listing of educational webinars sponsored by the IEEE Industry Applications Society.
Autors: Iqbal Husain;
Appeared in: IEEE Industry Applications Magazine
Publication date: Sep 2017, volume: 23, issue:5, pages: 71 - 71
Publisher: IEEE
 
» Steady Delivery: Wireless Local Positioning Systems for Tracking and Autonomous Navigation of Transport Vehicles and Mobile Robots
Abstract:
For many players in the service and manufacturing sectors, the cost associated with transportation processes is a key factor in competitiveness and market success. Innovations such as wireless connectivity, RF identification (RFID), and the Internet of Things have already transformed these industries, and this trend-stimulated by modern wireless technologies, wave-based imaging systems, and autonomous driving-is set to continue.
Autors: Yassen Dobrev;Martin Vossiek;Mark Christmann;Igor Bilous;Peter Gulden;
Appeared in: IEEE Microwave Magazine
Publication date: Sep 2017, volume: 18, issue:6, pages: 26 - 37
Publisher: IEEE
 

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